UKC

Tidal power

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It seems it takes a crisis to get the UK government thinking about energy policy. Predictably, nuclear is being talked up again as a source of baseload generation. So far, I haven’t seen tidal power mentioned. 
 

I think there are probably people on here who know a lot more than me about tidal generation, so what are the practicalities? I’ve seen 15 years quoted as a lead time for new nuclear (and we know the record on that). How long would tidal schemes take? Why aren’t there any already?

 girlymonkey 26 Sep 2021
In reply to rsc:

I believe there are a couple of tidal turbines running already and bigger ones being trialled. I can't remember where I heard by this, so someone more knowledgeable might correct me!

2
In reply to rsc:

It's predictable, good energy density and fairly low environmental impact (free stream anyway, followed by lagoon and lastly and most controversially barrage schemes).

Difficult and costly to install, maintenance usually requires lifting turbines out (again, mainly talking about tidal stream here, however Orbital has a clever solution for that) so needs weather / tide windows to align and good procedures for wet disconnecting etc. Long term reliability is a bit early to call. I would expect it to lag wind for a while due to the extra unknowns, and difficulty in being able to nip to site for a quick reset etc...

It'll need support for the short-medium term and probably some kind of payment bonus for being predictable. If it's left to free market forces, offshore wind will win out.

UK should be borrowing and investing in home grown companies now, for many reason (AKA Atlantis, Orbital Marine & Nova).

In reply to girlymonkey:

Yeah, 4 x 1.5MW in the Pentland firth (Simec Altantis) - Project Storma is apparently "in construction" but it seems to be struggling to get going by the looks of things.

Nova also has quite a few smaller turbines deployed.

Orbital Marine (was Scotrenewables) has the floating twin turbine design https://orbitalmarine.com/ - they're testing a larger version at EMEC just now.

In reply to Alasdair Fulton:

UK should be borrowing and investing in home grown companies now, for many reason (AKA Atlantis, Orbital Marine & Nova).

Couldn’t agree more. It’s good to hear that there are some small schemes at least under way. 

If it's left to free market forces, offshore wind will win out.

Well, market forces don’t seem to apply to nuclear…😀. I’d be interested to hear how people think the costs compare .

In reply to rsc:

Two things:

Tides move to their own drumbeat, so the peaks and troughs of power generated by any technology that uses it will have to be in step with that. You can play around with the operating regime and have two or four peaks of power a day, but you can't fully decide when these will be. Thus, a system that used tidal generation on a large scale would have to further solve the problem of the mismatch between when the power is generated and when it is most needed.

The Severn barrage, the largest tidal power scheme that the UK could have, would generate in a year the equivalent of about two big heat generating power stations, if my memory serves. That is, it would average about 2GW of power. That is a lot. However, it is a small fraction of the UK's electricity, never mind total energy needs.

David Mackay's seminal book 'Sustainability without the hot air' from a decade ago put it well, using back of the envelope calculations that any numerate person can grasp. He shows that, if fully exploited, the whole of tidal power generation in the UK,  not just the Severn, would generate about 4 kWh per person per day, whereas we use somewhere between 100 and 200 kWh per person per day, depending on where you draw the line.

That shows you the scale of the problem that needs to be solved for low to zero emission energy generation, wherever the energy solution lies on the reduction spectrum of total usage or carbon intensity.

 Si dH 26 Sep 2021
In reply to rsc:

The report commissioned in the Severn estuary options has lots of good information in it.

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/50064/1._Feasibility_Study_Conclusions_and_Summary_Report_-_15_Oct.pdf

It could be argued that some of the conditions stated under which a re review could be conducted (see section 8) have been met.

However, the Severn scheme is the biggest available due to the tidal range and according to that report could supply up to 5% of the UKs electricity needs in 2010. That 5% will obviously be smaller in the future as overall energy demand increases. Nuclear currently does around 20%. I can't see tidal ever providing the amount of baseload generation we need as a country, but it would be nice to see it contributing if they could mitigate the environmental impacts.

15 years is a bit pessimistic for a nuclear plant that already has a mature design and safety case I think, especially if not FOAK. The Hinkley Point C programme has obviously been fairly protracted overall but it's still a new technology (by which I obviously mean the EPR design - the first one went on grid in 2018) and the strike price for HPC wasn't agreed until 2013, which is 13 years from the forecast on-grid date. So not everything else has to, or should, follow the same path.

The big problem with nuclear cost is that because most of the cost is up front (as opposed to buying fuel through-life), you have to take out major loans to finance it. The interest payments form a huge portion of the overall cost and that's why people are looking at things like RAB models that reduce the risk to private investors, hence lower the interest rates. The energy prices forecast if that works are competitive with other energy forms. I suspect a large Tidal project must have the same problem so it might benefit from a similar scheme if it is ever taken forward. It's also worth noting that nuclear energy costs include an amount set aside for decommissioning, which others don't. The cost of decommissioning (eg) offshore wind has not been paid by anyone yet and the government will have to pay it (ie, take the money from taxation in future) if the operators are unable. Having said that, I've seen estimates online of £1-4bn to decommission all the UK's offshore wind turbines, which is not huge at national level.

Post edited at 16:10
In reply to rsc:

I don't get why we are not building more sustainable housing. Estates are popping up everywhere they can get planning permission.

Make it a condition of that permission that each house is south facing, has solar roof tiles and is linked to a central heat system running on a ground source heat pump and charge the house owners for the heat they use. 

In reply to Dax H:

Might be different in Scotland, but all the new schemes around here have solar.

Si DH - Western consumption has been dropping year on year. We're going to be shifting a lot of household heating to electric, but there are big targets for energy reduction and efficiency. 

In reply to mbh:

Interesting stuff. I’m surprised at the small proportion of UK electricity needs available from tidal: intuitively, you might think an island surrounded by seas with big tidal ranges would manage more than 2 - 5%.

Tides move to their own drumbeat, so the peaks and troughs of power generated by any technology that uses it will have to be in step with that.

Don’t the tides work their way (clockwise?) round the island, or have I made that up? That would provide a steadier source if the sites were spread out.

In reply to Si dH:

Useful link, thanks. I take your point that large scale tidal would have similar financing demands to nuclear. On decommissioning costs though, is there any meaningful way of estimating them for nuclear? 

In reply to Alasdair Fulton:

 Western consumption has been dropping year on year. We're going to be shifting a lot of household heating to electric

And I guess the shift to electric vehicles will add to demand (though offering potential storage to ease the need for baseload?)

Post edited at 17:27
In reply to rsc:

Yeah, they do work they way round. There's a good study somewhere showing you get a pretty consistent "uk wide" output if you have 5 or 6 major schemes dotted around.

 Si dH 26 Sep 2021
In reply to rsc:

>  Western consumption has been dropping year on year. We're going to be shifting a lot of household heating to electric

> And I guess the shift to electric vehicles will add to demand (though offering potential storage to ease the need for baseload?)

Total demand projection in this article.

https://www.icaew.com/insights/viewpoints-on-the-news/2020/nov-2020/chart-of-the-week-uk-electricity-projections

On nuclear decommissioning costs - it's not my specialism, but I don't see any reason why costs can't be forecast fairly straightforwardly for a new plant, accepting that there are big uncertainties in things like labour rates decades in the future, like with any longterm project. New designs now have to have detailed plans in place for waste storage for many decades, up to 100 years (for the same reasons, since 2017 Sizewell B has its own spent fuel storage facility with a 100-year design life.) The big problem with decommissioning older nuclear plants is that waste storage wasn't thought through as well when they were built, so stuff ended up being stored in places that wouldn't pass muster now, often without good records. When decommissioning an old plant, if you don't know what nuclear waste is stored where, especially in an inaccessible location, it makes the whole thing hugely more expensive and time consuming because you have to assume the worst and put measures in place to protect people.

Post edited at 17:46
 wintertree 26 Sep 2021
In reply to Alasdair Fulton:

> Yeah, they do work they way round. There's a good study somewhere showing you get a pretty consistent "uk wide" output if you have 5 or 6 major schemes dotted around.

Every time this comes up I’m amazed how desynchronised the tides are around Britain.

 tlouth7 26 Sep 2021
In reply to rsc:

Part of the problem of tidal power is scalability. We have a lot of offshore windfarms, but we are still fairly far from filling up the North Sea. Want more power? Build another windfarm.

In contrast, once you have used up the exciting bits of coastline and more dramatic river estuaries tidal power becomes a game of diminishing returns.

An issue with nuclear is that we price in the cost of mitigating the big dangers (meltdown, fallout etc), whereas for fossil fuels we don't (carbon emissions leading to, well, the apocalypse).

In reply to Si dH:

re decommisioning costs and old plants, interesting article in the FT weekend edition on this - with some lovely 1950's british comms about windscale.

 daWalt 26 Sep 2021
In reply to rsc:

> Interesting stuff. I’m surprised at the small proportion of UK electricity needs available from tidal: intuitively, you might think an island surrounded by seas with big tidal ranges would manage more than 2 - 5%.

tidal range is not necessarily a key parameter, you want a good tidal "race" - where the water is squeezed between two land-masses and accelerates to a decent usable flow speed. gives much better power / m2 of flow area.

similar to how wind was 20 years ago, all the prime sites are being looked at. it remains to be seen if designs can be tailored to lower sea-power sites.

Al Fulton's summary is spot on; saltwater, electricity, moving parts and watertight seals are a bastard combination to have to design around. All the developers are (broadly speaking) currently in the design development and testing phase in one way or another.

tidal turbines are also bespoke design for their site; blade design to suit the flow velocity (power), and foundations to suit the sea bed. But if the seals, bearings and elec gubbins can be designed to last underwater; blade design and foundations are not a massive issue to overcome.

their main benefit, and this is not trivial, is that you can predict with accuracy when your power can be generated. power storage is going to need to become a much more pertinent issue in the future

 deepsoup 26 Sep 2021
In reply to wintertree:

There's a nice animated map here:
https://www.windguru.cz/map/tide

 elsewhere 26 Sep 2021
In reply to daWalt:

> But if the seals, bearings and elec gubbins can be designed to last underwater 

Azimuth pods for ships have that sussed.

https://commons.m.wikimedia.org/wiki/File:Mackinaw_WLBB-30_Azipod_thruster.jpg

In reply to Alasdair Fulton:

> Might be different in Scotland, but all the new schemes around here have solar.

Fair play to Scotland. Shame Westminster won't follow their lead. 

 Philip 27 Sep 2021
In reply to Dax H:

> I don't get why we are not building more sustainable housing. Estates are popping up everywhere they can get planning permission.

> Make it a condition of that permission that each house is south facing, has solar roof tiles and is linked to a central heat system running on a ground source heat pump and charge the house owners for the heat they use. 

I have exactly the same question. Wouldn't even need to be distributed. The cost of a gshp collector is neglible at new build, and the pump is a fraction of the house selling price.

My EPC rated D house is cheap to heat on ASHP, so an A rated new build should be even better. Triple glazed, cavity and insulated walls, underfloor heating and 500mm of loft insulation. In build solar PV, with thermal store for DHW. Optional battery upgrade. New builds could be spec'd with supply that can take >4kw PV without issue so each house could have a good sized array to support EV or battery.

 gethin_allen 27 Sep 2021
In reply to mbh:

"whereas we use somewhere between 100 and 200 kWh per person per day, depending on where you draw the line."

These numbers seem rather high, where are they from?

I may be being thick but the peak electricity demand for the day seems to be around 32 GW. So split that with the 67.7 million ish people and you get a vastly different number.

In reply to elsewhere:

> Azimuth pods for ships have that sussed.


The problem is that tidal turbines have been required to be bolted to the seabed in deep water in order to not consitute a 'hazard to navigation'.  This requires them to resist much greater pressures than azipods bolted to the bottom of a ship, and the azipods can have their vulnerable electrical connections above the waterline anyway.

In reply to rsc:

The problem is that of maintenance. If you bolt a turbine to the seabed (as above) it's difficult to maintain, partially due to the strong tidal flows you'd want to install it in in order for it to be most efficient.  They have to be built much stronger than wind turbines due to the likelihood of objects being bundled into them by the tide like lost shipping containers and trawl nets. Heavy swell in exposed locations will affect the seabed as far down as 40m or so. There have been instances where trial turbines deployed on the seabed have simply disappeared without trace, literally washed away.

There have been trials of tidal turbines for many years now, but only this year (or last, I can't remember) have Atlantis developed something 'commercially viable', and even then the power they produce is around 25p per kW.  For them to be viable you'll need a large farm of them (economies of scale), and if something goes wrong that's a huge amount of money to lose.  I think the 'submarine hull with deployable turbine outriggers' type of design in the news recently is probably the most sensible - can be made by a shipyard and towed to and from position for installation and maintenance. But it does constitute a 'hazard to navigation', and thus could only be used in areas commercial vessels aren't expected to use. If used on a 'swinging mooring' they could expect to run for a higher percentage of the time due to being able to always be at the optimum angle to the current.

Post edited at 13:35
 elsewhere 27 Sep 2021
In reply to Toerag:

Oil rigs stick up out of the water and have exclusion zones. The hazard to navigation has already been a very distant second to energy supply.

4
In reply to elsewhere:

> Oil rigs stick up out of the water and have exclusion zones. The hazard to navigation has already been a very distant second to energy supply.


Yes, but they're in the middle of nowhere. Windfarms are also generally situated on sandbanks where commercial vessels avoid - that's why there aren't windfarms in the Thames estuary but there are either side of it and well out to sea. Areas of high tidal flow are in narrow passages and around headlands, for example the Alderney race is prime tidal power territory (possibly the best resource in the UK?) with peak flows up to 12knots on spring tides. However, the Race is used by ferries and cargo vessels daily.

Post edited at 14:37
 elsewhere 27 Sep 2021
In reply to Toerag:

Not all locations ideal for tidal power will be suitable.

Post edited at 14:44
 kipper12 27 Sep 2021
In reply to Dax H:

Should have been done years back!

In reply to gethin_allen:

The figure is from Mackay's book, here:

http://www.withouthotair.com  

It covers all energy usage, not just electricity.

The most striking way to think of this figure, I find, (and I can't remember if I got this from Mackay) is to recognise that one servant working for you all day, with an average power of 100 W, would provide you with about 1 kWh of energy per day. 

So a lifestyle that gets through 100 kWh per day, for transport, space heating, lighting and everything else, is a '100 servants' lifestyle. That's how energy intensive our lifestyle is and that's what we are asking low to zero carbon technologies to provide for us.

The figure is salutary when you see that all the engineering that would go into fully exploiting the tidal energy resource for the UK would provide less than 5% of that. 

Any LZC solution for the future necessarily comprises multiple options, even after energy reduction measures. Several combinations are possible, depending on what you least dislike having to put up with. Mackay suggests a few possibilities in one chapter.

In reply to the thread:

Well I was right to think there’d be some knowledge on here. But I was perhaps naively optimistic about the potential for tidal power. It’s good to hear there are some projects,  but it seems fast progress won’t happen without government backing. And I wanted to avoid this thread getting switched to the politics forum!

 gethin_allen 27 Sep 2021
In reply to mbh:

A very quick glance leads to many questions about the data and how it is skewed by inclusion of vehicle energy use.

A quick quote "we assume that a vehicle driven 100 km uses 80kw" this may be a reasonable ballpark for a medium car (80 kw being about 110bhp and driving an hour at 62 mph is reasonable).

The issue comes when you try to equate this to electric use as we are here when discussing tidal generation etc. 

If you're talking electric generation then you have to consider electric cars. Tesla claim their cars are 90% efficient and can travel 4.4 miles per kwh, 5.5 times further per kwh that the vehicle used in the calculations in that text you linked.

So if you consider that (using the daily peak energy demand not the 24 hr average to give a generous calculation) the average person uses 10 ish kwh of electricity per day and they are claiming people are 80kwh to drive an hour you can see how travel massively skews any calculations.

In reply to gethin_allen:

Interesting.

Transport currently accounts for 30-40% ish of total energy needs in the UK (I think - feel free to look it up)

If we assume that average driver does 50 km per day (see DfT for how wildly off this might be) then that is 40 kWh per person per day, at roughly 10 kWh per litre and 8l per 100 km. 

An ICE is roughly 20% efficient, let's say, and an electric motor 4 times more efficient, let's say. 

So in an electric transport future, transport energy needs might be 25% of what it is now, or more, allowing for economic growth. Maybe as much as 50% of now. Who knows.

Look at Mackay's Ch 27 - he was [sadly, he died] no dummy - A Professor of Physics at Cambridge who became advisor to DECC on the back of this book. Even allowing for the efficiencies in heating and transport due to better buildings and electrification of transport, partly negated by the increased electricity demand for more gizmos, we still go from a need of (he estimates, and it's not hard to follow his reasoning) from an estimate 125 kWh pppd to about 70. Even that is hard to meet in a low carbon way.

 Richard J 27 Sep 2021
In reply to gethin_allen:

Last time I worked out the numbers what I came up with for the UK was 90 kWh per person per day total, 35 kWh for petrol and diesel for cars and trucks, 21 kWh for gas to heat houses and hot water, and 30 kWh for the inputs into power stations to produce the 14 kWh of electricity we use.  (You can get the raw numbers from a govt publication called Digest of UK energy statistics, these numbers were from DUKES 2018 converted into kWh per person per day). On top of that there’s probably about 40-50 kWh of “embedded energy” in the stuff we buy.  Aviation also not included.  

You’re right that electric vehicles are more efficient than internal combustion engines: we might get the 35 kWh down to 10 kWh of electricity if all petrol & diesel vehicles came off the road.  Of course, that would need a big increase in zero carbon electricity generation.  

In 2018 we had about 2.5 kWh per person per day of wind and solar and 3 kWh of nuclear.  By 2030 we might get wind and solar up to 7 kWh or so but we’ll have lost much of the nuclear. There’s still a big gap.

Post edited at 19:19
 stevieb 27 Sep 2021
In reply to Dax H:

> I don't get why we are not building more sustainable housing. Estates are popping up everywhere they can get planning permission.

Unfortunately, there’s a reason why house builders give huge donations to political parties 

 Yanis Nayu 27 Sep 2021
In reply to Dax H:

And as a form of QE, stick solar panels on houses, stick wind turbines etc in villages. 

 Jim Fraser 30 Sep 2021
In reply to rsc:

I have worked for companies doing wind, wave and tidal. Tidal is definitely the biggie. It's the only one of the three that is "Always ON". Yes, the tide periodically relents and turns but when the tide is rising in Strangford Lough, it's doing something quite different at Kylerhea, so across the country generation is continuous. 

As hinted at above, navigation is problematic. Very problematic.

Maintenance can be a problem since the operating environment is unrelentingly difficult. A major maintenance problem is keeping sea water away from electrical components. At least one manufacturer has attempted to side-step this by creating a generator that operates in a completely flooded sea water environment. 

In reply to rsc:

> UK should be borrowing and investing in home grown companies now, for many reason (AKA Atlantis, Orbital Marine & Nova).

The scandal is the charges to access the national grid scale basically with distance from London so green energy projects in Scotland pay far more than power generation in SE England and projects in the far north like tidal power in the pentland firth get totally screwed.

This is the kind of sh*t you get when the regulator is in London.  Of course they think the generators which are furthest from the consumers should pay the most for the connection: if the regulator was in Inverness they'd probably think that consumers who are furthest from generators should pay more.    

http://www.scottishenergynews.com/higher-connection-charges-in-scotland-than-ruk-are-no-barrier-to-electricity-generators-says-national-grid-chief/

13
 Wire Shark 30 Sep 2021
In reply to rsc:

> Well I was right to think there’d be some knowledge on here.

I think the key word here is some.  What you're not in a position to assess is the quality (not a criticism, neither am I on this topic).

What I do know is that whenever the one topic comes up that I do actually know a lot about, that there's an awful lot of armchair commentators confidently proclaiming a total lot of nonsense.  This tends to make me take anything else talked about "knowledgeably" here with a rather large pinch of sodium chloride.

Personally, I'd search for the opinions of acknowledged experts in the field rather than take the opinions of this lot as gospel.

Post edited at 05:08
2
 wintertree 30 Sep 2021
In reply to deepsoup:

> There's a nice animated map here:https://www.windguru.cz/map/tide

That's fantastic thanks.  Really drives home two things discussed on the thread:

  • Why the British Isles always has access to tidal power, despite being much smaller than the tidal bulge
  • Why the best areas for tidal turbines are prime shipping lanes

New Zealand and everything from Thailand to Northern Australia look pretty good in terms of constant access to tidal power too.  A shame there's not a version of the map showing d/dt of the water height.

In reply to Wire Shark:

> Personally, I'd search for the opinions of acknowledged experts in the field rather than take the opinions of this lot as gospel.

It’s true everyone has an angle, if not an axe to grind  - but that includes acknowledged experts, perhaps even more so.

As an A-level teacher of an essay-based subject, I pride myself on my instinct for detecting bluff!

 deepsoup 30 Sep 2021
In reply to wintertree:

> A shame there's not a version of the map showing d/dt of the water height.

I don't think you'd go far wrong just assuming d/dt of the water height to be proportional to the tidal range.

Apart from a few anomalies caused by bays filling and emptying and such, the variation of the height of the water around the UK is more or less sinusoidal with a period of 12 and a bit hours. 
(With the amplitude modulated by another sinusoid with a period of about 14 and a bit days as the tides caused by the Sun drift in and out of phase with those caused by the Moon and we go from springs to neaps and back again.)

If you want to anchor a turbine of some kind in flowing water though (as opposed to building a lagoon or something), d/dt of water height isn't all that helpful - the flow of the water is more complicated and essentially comes about from the water being constricted in some way. 

For example on the West coast of Ireland there's hardly any flow because it's open to the Atlantic so the flow of the water arriving as the tide is rising is diffused across the entire coastline, whereas the Irish Sea flows quite rapidly North for six and a bit hours then South again as water is constantly being pushed in or pulled out between Ireland and Wales at one end or Northern Ireland and Scotland at the other.

There are Admiralty tidal stream atlases that give you a pretty good idea of how the water moves (horizontally) around the UK, but I don't think there's anything online as pretty as that animation there.  You can at get a look at those UK regional tidal atlases for free though, here:
https://www.visitmyharbour.com/articles/category/842/tidal-streams/

In reply to Wire Shark:

I did do my MSc thesis on novel techniques in determining blade loads due to wave induced velocity shear, using drivetrain condition monitoring sensors on the Atlantis AR1500. I would not profess to be an "expert in the field", but I do have a basic understanding... 

What's your special subject?

1
 jkarran 01 Oct 2021
In reply to rsc:

> I’ve seen 15 years quoted as a lead time for new nuclear (and we know the record on that). How long would tidal schemes take?

I don't think we will ever see any really large (Severn scale) barrages built around the UK. I suspect as happened with offshore wind we will see quite rapid deployment of floating energy harvesters*, the technology maturing and starting to reach significant scale within a decade.

*probably turbines under barges but there are several promising options for tidal flow generation, it's not clear which if any one in particular will win out, they may all find niches.

I also think we will start to see storage integrated into renewable generation offshore, particularly as we move into deeper water opening up significant gravitational potential energy/buoyancy storage opportunities sharing sub-sea anchoring and power infrastructure with the generators.

> Why aren’t there any already?

Because it's very expensive and market driven.

It's a very harsh and capital intensive environment (which didn't stop us exploiting coal or offshore oil and gas!) but particularly for an island nation it's a huge untapped resource.

jk

Post edited at 10:13
 jkarran 01 Oct 2021
In reply to mbh:

> Tides move to their own drumbeat, so the peaks and troughs of power generated by any technology that uses it will have to be in step with that. You can play around with the operating regime and have two or four peaks of power a day, but you can't fully decide when these will be. Thus, a system that used tidal generation on a large scale would have to further solve the problem of the mismatch between when the power is generated and when it is most needed.

The UK has tidal races that are sufficiently out of phase we could in theory extract near perfect 3-phase tidal power requiring very little if any storage dedicated to improving its load factor.

Personally I suspect the explosion of EVs over the coming decade and the opportunity it brings for a large fraction of our electricity demand to consume intelligently is going to reduce our need for more storage dedicated to smoothing short term (<24H) fluctuations in power availability. However the move to ever higher fractions of renewables (mostly essentially solar powered directly or indirectly) will drive development of multi-day storage which I suspect will be predominantly chemical and thermal, building on the existing assets, both generation and fuel storage, left stranded by our move away from fossil energy.

We already make good use of solar power which while it does partially synchronise with our consumption at least for a couple of seasons, offers no such practical opportunity for 24/7/365 generation. In part that's because it's become very cheap.

jk

Post edited at 10:35
In reply to jkarran:

> I also think we will start to see storage integrated into renewable generation offshore, particularly as we move into deeper water opening up significant gravitational potential energy/buoyancy storage opportunities sharing sub-sea anchoring and power infrastructure with the generators.

I don't - why build in a harsh, expensive environment when you don't have to? Much easier to build a gravity tower on land rather than offshore. The only real advantage for offshore storage would be to do 'peak lopping' of the output and facilitate cheaper power cables to shore. As tidal power is predictable, the need for storage capacity is much reduced compared to wind or solar which need to be oversized to cope with the reduced outputs at random times. - planned shutdowns of other generation capacity isn't a problem.

In reply to Alasdair Fulton:

> I did do my MSc thesis on novel techniques in determining blade loads due to wave induced velocity shear, using drivetrain condition monitoring sensors on the Atlantis AR1500. I would not profess to be an "expert in the field", but I do have a basic understanding... 

Do you have any interesting tidbits of information you can tell us? Like the forces involved.

In reply to deepsoup:

> If you want to anchor a turbine of some kind in flowing water though (as opposed to building a lagoon or something), d/dt of water height isn't all that helpful - the flow of the water is more complicated and essentially comes about from the water being constricted in some way. 

> For example on the West coast of Ireland there's hardly any flow because it's open to the Atlantic so the flow of the water arriving as the tide is rising is diffused across the entire coastline, whereas the Irish Sea flows quite rapidly North for six and a bit hours then South again as water is constantly being pushed in or pulled out between Ireland and Wales at one end or Northern Ireland and Scotland at the other.

Yep. Alderney's tidal range is about 8m on springs compared to St. Malo's 14 metres, however the flows round Alderney are twice those near St.Malo simply because all the water from the bay of St.Malo is dragged up either side of Alderney and round Cap De La Hague - in the bay itself it just goes up and down (relatively speaking). The volumes of water involved are bonkers -the Alderney race will see average speeds of about 8 knots through it at peak flow on spring tides, meaning ~2,400 tonnes of water a second are passing through it. You can watch the open sea literally piling up in front of headlands and reefs before flowing past them (see pic attached - a crazy Alderney angler fishing in 5.5 knots of tide.  The sea surface slopes down by about 2 feet in 10yards).  It's estimated the waters within 3 nautical miles of Alderney have the realisable potential for 1-3GW of tidal power, and a slightly smaller amount on the French side.

Post edited at 15:34

 henwardian 01 Oct 2021
In reply to rsc:

1) The sites for effective power generation are very limited.

2) Submersing your equipment in salt water is dire for its longevity and hence electricity cost.

3) building things under the sea is a difficult and expensive process.

There are fair number of other issues as well but I guess it all boils down to the people in know crunching the numbers and just not being able to see how it could effectively compete, even on the other side of a load of money being poured in to develop it.

It does all come down to money in the end because you have a finite amount of money (ok, finite amount of productive capacity if we are being finicky) and the environmental question has to be: "If I can save 1 tonne of CO2 by investing £100 in wind, but it takes £1000 in tidal, what else could I achieve with that extra £900?". I do wonder whether direct CO2 removal will one day become the solution to needing fossil fuels to continue to play their part in the baseload.

 jkarran 01 Oct 2021
In reply to Toerag:

> I don't - why build in a harsh, expensive environment when you don't have to? Much easier to build a gravity tower on land rather than offshore.

Scale: At sea the h term in m.g.h easily can be order of magnitude bigger than for the biggest conceivable tower type store.

Safety: If it fails there's nobody for it harm.

NIMBY: Offshore it's invisible, a thousand foot pile of concrete Lego or a pumped storage dam really isn't.

Material efficiency: Buoyant systems can potentially displace thousands of tons with little more than a big balloon, a lot of cable and a big ground anchor.

Opportunity: Floating systems (wind particularly being intermittent) have the opportunity to re-use much of their existing infrastructure to support small to medium scale storage as part of the overall system.

Environmental: No need to build lagoons or dam valleys (see also NIMBY), no need to compete with automotive for battery resources.

> The only real advantage for offshore storage would be to do 'peak lopping' of the output and facilitate cheaper power cables to shore.

That's an interesting point regarding cabling. Is peak-rated export infrastructure a significant fraction of a system build cost when compared to average-rated cabling/transformers etc?

As power becomes more intermittently available across the whole network the opportunity to store then sell it on at a more favorable moment becomes increasingly valuable, what now looks difficult and expensive increasingly looks like missed opportunity. Offshore wind was predicted to be too difficult and costly to take off. A decade on costs have kept falling and installed capacity has massively exceeded early predictions. Floating generating systems have a huge ready made void beneath them into which something can be dropped (or floated) and they already have the export infrastructure already in place.

jk

 jkarran 01 Oct 2021
In reply to Dax H:

> Make it a condition of that permission that each house is south facing, has solar roof tiles and is linked to a central heat system running on a ground source heat pump and charge the house owners for the heat they use. 

Better, plan to put the PV into the east and west facing roofs of new build, broaden the solar power peak well into the morning and evening. No individual would choose to do that with their own solar system where south facing is available but a planned system would.

South facing surfaces (vertical mainly to exploit low winter sun and avoid summer overheating) could then be used for passive solar heating.

jk

In reply to jkarran:

One of the major drawbacks to any kind of energy arbitrage / peak shaving is that it has the inherent risk that if it is too successful, the pricing differentials get reduced and the business model falls over.

Hence why the grid has to directly incentivise it.

Would you invest £xxM extra with the risk that it might be idle and worthless in 5 years? Not without guarantees...

(not saying we *shouldn't* do it, we'll have to, but it is unlikely to happen on the free market.) that said, we're working on battery storage or H2 production and storage / export on sites that are already grid constrained, and cannot export peak power all the time. On those sites the sums add up. 

In reply to Toerag:

I didn't get that involved the design. Tbh the whole thing /project was a bit frustrating as I ended up only getting a week of testing, a few weeks before my thesis was due. The plan had been to use live data from when it was in the water, but in the end I only got a week of data on the test bed in Blyth.

The only interesting thing I found out was the the frequency modulation (recorded as added load on the bearings etc.) you'd get from waves was around the same frequency as the modulation you already get from the planet gears rolling last the accelerometers. You could tell them apart as the FM from the gears scales with rotor speed, waves didn't. That said, I had to synthesis my wave data so it was all a bit of a disappointing fudge in the end.

I think my main conclusion was that you *could* (in theory) get the loading from the vibration sensors, you're much better off spending the extra at the design stage and just installing fibre optic strain gauges into the blades. Tried and tested! 

In reply to tom_in_edinburgh:

> The scandal is the charges to access the national grid scale basically with distance from London so green energy projects in Scotland pay far more than power generation in SE England and projects in the far north like tidal power in the pentland firth get totally screwed.

> This is the kind of sh*t you get when the regulator is in London.  Of course they think the generators which are furthest from the consumers should pay the most for the connection: if the regulator was in Inverness they'd probably think that consumers who are furthest from generators should pay more.    

Did you read National Grid's response in the article you linked to? It clearly states that the higher connection costs in Scotland (2015/16 anyway) are driven by the existing local differential between generation and consumption - very high and very low respectively - not simply the distance from large population centres.

A hypothetical generator in Cornwall getting a subsidy is due to the lack of generation down there, with NG currently having to invest in reactive compensation (shunt reactors, cap banks etc) to account for long expanses of overhead lines far from generation and the capacitive and inductive effects that result.

The cost of connection is based, in part, on the amount of network reinforcement that the new connection would require, which can be much more far reaching than you might first suspect. Sat in early development meetings for a potential Cardiff Bay tidal lagoon connection, whether you located the substation in S. Wales or across the Bristol Channel in Somerset the power flows would melt the existing Severn Tunnel cables and require network reinforcement as far away as Cowley substation near Oxford.

In reply to Alasdair Fulton:

This thread continues to throw up interesting things I didn’t know I didn’t know.

Now I’m wondering about distribution through the grid. On one of the documents linked early on in the thread (DUKES I think), I noticed that losses in transmission were an astonishingly large proportion of power generated. This suggests to me (to repeat, an interested but badly informed non-scientist) that small local generation, close to point of use, would make more sense. Is this where we’re heading anyway with renewables?

 wintertree 01 Oct 2021
In reply to rsc:

>  I noticed that losses in transmission were an astonishingly large proportion of power generated

Rather excitingly,  the work that's been done for high temperature superconductor (HTS) cabling for fusion reactors has got to the point that it's now economically viable to install HTS cables for grid transmission under certain conditions, even accounting for the cost of the cryogenics plants. 

Latest example:

https://www.nexans.com/newsroom/news/details/2021/09/2021-09-02-pr-nexans-installs-and-commissions-superconducting-cable-for-chicago-resilient-electric-grid-project.html

I love HTS cables.  If you get to handle one that's got a cut and polished cross section, it's just phenomenal.  If we ever have a catastrophic loss of technology and knowledge, future archeologists are going to really scratch their heads over these.  At least until they get technology back down to LN2 temperatures...

In reply to wintertree:>

> I love HTS cables… If we ever have a catastrophic loss of technology and knowledge, future archeologists are going to really scratch their heads over these. 

I think the fall-back explanation is usually “ritual significance” (apologies to archaeologists, including Mrs rsc).

In reply to rsc:

> This thread continues to throw up interesting things I didn’t know I didn’t know.

> .....I noticed that losses in transmission were an astonishingly large proportion of power generated. This suggests to me ....  that small local generation, close to point of use, would make more sense. Is this where we’re heading anyway with renewables?

It depends. The efficiency of a solar array is scale invariant, more or less, since it is just lots of small panels strung together, whereas the same is not true of wind turbines. Large, wind farm scale ( 3MW each rated power or more) turbines pay for themselves in energy and carbon outlay terms within months, whereas, at the other extreme, the little ones you see on yachts and coastguard stations, while useful, cost more in either sense to make than they ever generate or save. 

The biggest turbines are close to the limit of what it is possible to extract from the wind. Smaller, 0.5 - 1 MW turbines, of the sort that a community might put up and examples of which are all over the county I live in, are some some way behind.

So in energy terms, from this limited perspective, smaller and more distributed does not necessarily make sense, yet it may have benefits in terms of local ownership, and the impact this could have on local economies and engagement in a low carbon agenda. The island of Samsoe in denmark is a good example of what can be achieved.

In reply to rsc:

> This thread continues to throw up interesting things I didn’t know I didn’t know.

> Now I’m wondering about distribution through the grid. On one of the documents linked early on in the thread (DUKES I think), I noticed that losses in transmission were an astonishingly large proportion of power generated. This suggests to me (to repeat, an interested but badly informed non-scientist) that small local generation, close to point of use, would make more sense. Is this where we’re heading anyway with renewables?

I'd say that the more disbursed weather-dependent renewables like wind and solar are the better due to the simple fact that it may not be sunny or windy *here* but it may be sunny and windy *there*. Things like mini nukes and other local small factor generation certainly have their advocates but you still want as much interconnectivity as possible for flexibility and resilience during planned or unplanned outages..

An often overlooked issue surrounding localised generation is low power flows resulting from generation and demand being very closely matched locally. No.1 it makes the protection and control equipment's job, i.e. primarily to detect faults and automatically trip, re-close and re-trip if the fault is persistent, harder due to lower current flowing over a given circuit (national scale north to south flows are diminishing already due to embedded generation at distribution level), and this presents a problem even in on-load commissioning/testing as you need a minimum current flow to be confident your protection settings are correct. No.2 lower current flows reduce system inertia which increases the likelihood of a cascade trip when you lose a generator unplanned. This problem is also compounded by the retirement of the large old spinning generation from large scale power stations in favour of smaller, embedded and non-spinning generation like solar. National Grid had actually struck a deal with (I think) Ratcliffe-on-Soar or Drax for the grid to actually power their old generator turbines to back feed the grid in turn with the reactive power and resultant increased inertia that heavy spinning generation used to bring as a by-product of the active or true power it produced.

I hope I've not mangled my explanation above - I've been a project engineer for 13 years and my power systems textbooks are gathering dust.

Post edited at 22:41
In reply to MonkeyPuzzle:

> Did you read National Grid's response in the article you linked to? It clearly states that the higher connection costs in Scotland (2015/16 anyway) are driven by the existing local differential between generation and consumption - very high and very low respectively - not simply the distance from large population centres

I really don't care what English people sitting in London think is fair to charge power generators in Scotland.   What Scotland needs is to regulate its own industries and to trade green electricity with England at arms length, and seeking to achieve the best price.   If the English want green power and they want their lights to stay on then they pay up or we put in a cable to the EU and sell it to them instead.

12
In reply to tom_in_edinburgh:

Yeah, you'll still need to pay to reinforce the network whether it's through your bills or your taxes.

In reply to MonkeyPuzzle:

> Yeah, you'll still need to pay to reinforce the network whether it's through your bills or your taxes.

Wrong.

Scotland exports vast quantities of power, our capacity is way beyond what we need for our own population: the cost of the infrastructure to get the green electricity from wind farms in Scotland to England needs to get added to the bills of the customers in England.

https://www.gov.scot/binaries/content/documents/govscot/publications/statistics/2018/10/quarterly-energy-statistics-bulletins/documents/energy-statistics-summary---march-2021/energy-statistics-summary---march-2021/govscot:document/Scotland+Energy+Statistics+Q4+2020.pdf

9
In reply to tom_in_edinburgh:

Or we'll just incentivise connections where there isn't massive over-generation (as per the connection charges), fast-tracked in the event of independent Scotland so as not to have essential infrastructure outsourced to a foreign country.

Building loads more generation than you need as a nation and then telling your neighbour to pay extra for the energy isn't a great business plan, but you're welcome to try.

In reply to tom_in_edinburgh:

Fun fact: My current project is a wide area Operational Tripping Scheme (OTS) that's required because of all the embedded generation connected to the Distribution level network that the NG Control Centre can't "see". It monitors circuits likely to be affected by excess power flows from that embedded generation and, in the event a circuit is running too hot, sends a trip signal to the Distribution Network Operator which gives them a generous (~2 minutes) window in which to select a generator to drop before we just ditch an in-feed for them. It's part of their connection agreement.

But sure, an independent Scotland can *force* us to pay for network reinforcement to buy their excess generation.

In reply to tom_in_edinburgh:

> I really don't care what English people sitting in London think is fair to charge power generators in Scotland.   

You’d want to be really sure there aren’t any Scottish people involved in National Grid decisions before making a daft comment like that.

When I started this thread I wanted to learn about tidal power, so I tried to nudge the discussion away from nuclear. In fact, poster(s) with inside knowledge of the nuclear sector have been constructive and balanced.

 I must admit I didn’t anticipate an SNP angle. I underestimated you!

In reply to MonkeyPuzzle:

> I hope I've not mangled my explanation above - I've been a project engineer for 13 years and my power systems textbooks are gathering dust.

I think I just about follow it- thanks! - though I’m on a steep learning curve here.

Am I right then in thinking that thermal (“spinning “) generators sometimes keep the lights on simply through inertia? For some reason, I find that brilliant and hilarious at the same time!

In reply to rsc:

> I think I just about follow it- thanks! - though I’m on a steep learning curve here.

> Am I right then in thinking that thermal (“spinning “) generators sometimes keep the lights on simply through inertia? For some reason, I find that brilliant and hilarious at the same time!

Kind of. They're synchronous generators which means they spin at (in the UK) 50Hz or revolutions per second. Maintaining a system-wide consistent frequency at 50Hz is essential to prevent the network collapsing. If you look at the network frequency just as the two generators were lost before the 2019 blackout, you see it fall off a cliff, leading to the network cascade. With proportionally less synchronous (coal, gas, nuclear, oil) generation and more asynchronous (solar, wind, hydro, interconnectors, anything DC basically) generation, system inertia is less as a result. That's why NG has a deal in place with old retired synchronous plants that have been repurposed, with the old turbines actually becoming shunt motors powered by the grid rather than vice versa, with the output providing reactive power and adding to system inertia.

When reconnecting a synchronous generator to the grid the operators used to have to match two sets of three lamps alternating light and dark to make sure that the three phases of the generator were at the same frequency (and in the same sequence) as the grid before throwing the switch to connect. Get it wrong and the shock destabilises the grid and most likely totals your generator. All automated now - boring!

 fred99 02 Oct 2021
In reply to tom_in_edinburgh:

> The Highlands exports vast quantities of power, their capacity is way beyond what we need for our Central Belt population: the cost of the infrastructure to get the green electricity from wind farms in the Highlands to the Central Belt needs to get added to the bills of the customers in Glasgow/Edinburgh.

Fixed that for you.

 wintertree 02 Oct 2021
In reply to MonkeyPuzzle:

> When reconnecting a synchronous generator to the grid the operators used to have to match two sets of three lamps alternating light and dark to make sure that the three phases of the generator were at the same frequency (and in the same sequence) as the grid before throwing the switch to connect. Get it wrong and the shock destabilises the grid and most likely totals your generator. All automated now - boring!

My copy of the Children’s Encyclopaedia has a description of the process as it was in the early days. The engineer had a dial whose needle rotated proportional to the frequency difference, or whose rest position showed the phase difference when in sync.  They relayed commands down to the turbine operator using a lever like the ones that signalled “all ahead full” etc to the engine room of a ship.  Fantastic.

The popularity of “digital inertia” is rocketing with smart inverter/charger battery units in the multi MW range being installed to improve stability and avoid grid cascade failure.  Big in Australia recently.  In theory this is a good thing but I suspect it’ll end up back at the same place as the operators pair back the margins elsewhere…

In terms of rsc’s previous comment it might be worth stepping back and explaining that “inertia” here means the grids resistance to change in frequency; this is partly down to spinning parts and their inertia and the energy stored in their rotation, but there are other forms of “inertia” including reactive stuff (electrical energy stored in the fields) and control responsive stuff like demand shedding or denorwic - different forms of inertia kick in on different timescales; spinning up old turbines will be useful for the fastest timescales (sudden supply or demand spikes in less than a second).  Managing inertia on the fastest timescales is critical to keep the system together long enough to engage slower mechanisms such as selective load shedding or spooling up stored hydro.  Future bidirectional links could provide a distributed digital inertia if they’re smart enough.

Post edited at 14:53
In reply to MonkeyPuzzle:

> When reconnecting a synchronous generator to the grid the operators used to have to match two sets of three lamps alternating light and dark to make sure that the three phases of the generator were at the same frequency (and in the same sequence) as the grid before throwing the switch to connect. Get it wrong and the shock destabilises the grid and most likely totals your generator. All automated now - boring!

I'm sure I saw something like that a few years ago at Mary Tavy hydroelectric power station in Devon, where the kit (3 x Francis Turbines + 3 x Pelton wheels, each with its alternator, dates from the 1930s, give or take a Trigger's broom or two. Your description rings a bell with what were told, anyway.

https://www.southwestwater.co.uk/siteassets/documents/mary_tavy_a5_leaflet.pdf

I can't remember whether what we were shown was just how they used to do it, or how they still do it now.


In reply to wintertree: 

> In terms of rsc’s previous comment it might be worth stepping back and explaining that “inertia” here means the grids resistance to change in frequency;

Ha! You’re right that I’d misunderstood. So “inertia” is being used both literally and metaphorically? Makes more sense, I guess.

In reply to MonkeyPuzzle:

> Or we'll just incentivise connections where there isn't massive over-generation (as per the connection charges), fast-tracked in the event of independent Scotland so as not to have essential infrastructure outsourced to a foreign country.

> Building loads more generation than you need as a nation and then telling your neighbour to pay extra for the energy isn't a great business plan, but you're welcome to try.

I was going to say something similar, but couldn't quite word it right. Basically, what he said ^^^ and that's coming from someone who wants Indy, doesn't dislike England and works in Renewables. 

Put it another way. If you're selling electricity, the cheapest you can sell it is your running costs, plus finance / build costs etc. etc. etc. plus the cost to distribute to wherever the point of sale is. You can't sell electricity to London from Caithness. So the "sale price" will include the distribution cost, if that's more that the cost of other, locally produced energy, then reckon they'll still buy ScotWatts?

Also, Tom, say England builds nukes, or loads of wind, or just regresses and reopens the coal stations, resulting in a massively reduced need for ScottWatts (I like this term, just made it up). If, like you say, we would want to sell our ScottWatts to Europe. Reckon they'll foot the bill for the interconnector? Or do you think it's more likely we'd either 1, dial down the non-renewables or, 2, have to build the infrastructure ourselves to give us access to the EU market? 

No matter what your political viewpoint is, you can't get around the fact that shifting energy around in cables long distances is costly to build, lossy and costly to maintain. 

In reply to rsc:

They typically spin up the big rotating generators to above 50Hz prior to expected peak demands, as the extra energy stored as "excess speed" can be used to manage short peaks in demand. 

A lot of wind turbines match grid frequency, and need a "stable" grid to get synchronised, but more and more they're having full-scale electrical converters (convert the variable frequency AC generated by the turbines to DC, and then back to AC 50Hz). These can actually be used for grid support and black start, or reactive power control etc.

In reply to MonkeyPuzzle:

> But sure, an independent Scotland can *force* us to pay for network reinforcement to buy their excess generation.

England doesn't have enough power and committed to green energy.  Take away Scotland and your lights go out.  It is that simple.  Right now we can't use our leverage effectively, as an independent nation we could.

Also: there's lots of things to do with excess electricity.  For example you could make hydrogen or run cryptocurrency mines.   I'd find it very amusing if England had to pay more for its power when Ethereum or Bitcoin price was high.

16
 wintertree 04 Oct 2021
In reply to tom_in_edinburgh:

>   I'd find it very amusing if England had to pay more for its power when Ethereum or Bitcoin price was high 

Where-as I find it absolutely tragic that this technology has risen to prominence in part due to its utility to drug dealers, money launderers, extortionists and child abusers and despite its absolutely horrific environmental costs.

A prime example of technology making things worse in pretty much every way, other than for those profiting from it.

1
In reply to Alasdair Fulton:

> Also, Tom, say England builds nukes, or loads of wind, or just regresses and reopens the coal stations, resulting in a massively reduced need for ScottWatts (I like this term, just made it up). If, like you say, we would want to sell our ScottWatts to Europe. Reckon they'll foot the bill for the interconnector? Or do you think it's more likely we'd either 1, dial down the non-renewables or, 2, have to build the infrastructure ourselves to give us access to the EU market? 

One would expect ScottWatts could be sold to Europe via the national grid and the England - mainland EU interconnects. Yes, it would be expensive as the grid takes its cut, and I dunno if the interconnects are big enough, but it would be doable, and doable in short timeframe - putting in a couple of Scotland - mainland EU interconnects through the north sea is going to take many years, if indeed it is even financially viable.

Post edited at 11:30
 wintertree 04 Oct 2021
In reply to Alasdair Fulton:

> Reckon they'll foot the bill for the interconnector? Or do you think it's more likely we'd either 1, dial down the non-renewables or, 2, have to build the infrastructure ourselves to give us access to the EU market? 

Another approach could be to use the surplus to produce liquid hydrocarbons from captured atmospheric CO₂.  Synthetic kerosene is going to be a mainstay of post-fossil civil and military aviation for the next few decades (at least), and there's growing interest in synthetic petrol as well.  I've wondered before if seasonal synthetic fuel production has a role to play in dealing with the seasonality of solar.  Power to methane seems an obvious one given the gas grid storage capacity.

https://arstechnica.com/cars/2021/09/porsches-new-synthetic-gasoline-may-fuel-formula-1-races/

In reply to tom_in_edinburgh:

> I really don't care what English people sitting in London think is fair to charge power generators in Scotland.   What Scotland needs is to regulate its own industries and to trade green electricity with England at arms length, and seeking to achieve the best price.   If the English want green power and they want their lights to stay on then they pay up or we put in a cable to the EU and sell it to them instead.

Would that be "scotland's" green energy paid for by a subsidy added to every household bill across the UK? 

Post edited at 15:31
1
In reply to Toerag:

> putting in a couple of Scotland - mainland EU interconnects through the north sea is going to take many years, if indeed it is even financially viable.

Hasn't a 1.4 GW Northumberland-Norway interconnect just been commissioned? It took less than 10 years to build. BBC says it cost €1.6bn.

In reply to rsc:

Apologies if it was and I missed it.. but what hasn't been discussed here amongst the talk of tidal frequencies, range, blades and whatnot is the environmental impact.

Very roughly speaking tidal power falls into 2 camps.

Stick something in the water  -- like the Orkneys and Orbital Mariner's 2MW turbine. Excellent stuff but locations where this pays off are limited as they need fast flows where the tide can race. But this approach has promise

Or build a dam across an estuary -- like La Rance (or various proposed Severn Estuary schemes). The problem with those is that by restricting the flow to build a head of water to power turbines, the tidal range on the landward side is dramatically reduced. The coastal habitat, like tidal mudflats that feed birds at low tide and tidal creeks etc are dramatically reduced. The cost to the environment is huge, hardly "clean" power.

Just thought I'd throw it out amongst the tide sloshing in bays and all that discussion, that where tidal power generation can be sited is as much an environmental question as an engineering question, especially the barrage approach.

Enjoy...

Post edited at 16:28
In reply to CantClimbTom:

Since the barrage at La Rance has been in place for over 50 years, there should by now be a mature assessment available of the environmental impact it has had. Do you know of one? I'd be surprised if it was wholly negative.

Also, do you know to what extent the details of the environmental impact are altered by the operation mode - ebb, flood or both?

Post edited at 16:55
In reply to mbh:

The issue is more what would be the impact to Severn Estuary or Wherever a proposed scheme is, rather than what happened at La Rance as each site is individual.

That said, there have been studies on exactly that, such as https://scholar.google.co.uk/scholar?q=la+rance+environmental+impact+study&hl=en&as_sdt=0&as_vis=1&oi=scholart#d=gs_qabs&u=%23p%3DL2v6U2tbgdoJ

In reply to CantClimbTom:

Well, yes, but we can always learn from what happened elsewhere. 

There would undoubtedly be an environmental impact of a Severn barrage, as with any major infrastructure project. From that perspective, however, the issue is more whether there is a better alternative.

In reply to wintertree:

Wood PLC and Honewell have just announced a collaboration on carbon neutral* aviation fuel.

https://www.woodplc.com/news/latest-press-releases/2021/wood-and-honeywell-introduce-technologies-for-carbon-neutral-sustainable-aviation-fuel

Haven't looked into it in much detail....

 jkarran 04 Oct 2021
In reply to CantClimbTom:

You don't strictly need the strongest races, they're just where the energy is densest. There are various spinning/flapping/swimming ideas aimed at exploiting lower flow areas and of course putting turbines in long breakwater/jetty structures to tap longshore flows. Can't see that being profitable (in money or carbon) unless the structure is multifunction and of course nothing is without impact. 

As for barrages/lagoons, to what degree is the upstream range actually reduced? I can see the tide gets out of phase across the dam and the tidal sinusoid is presumably squared up a little upstream but you still need the swing in the upstream pond to extract the tidal fraction of the energy available. The more swing the more you extract so you still have tidal wetlands behind the barrage. Anyway, I can't see the Severn project getting funded and approved before it's a redundant idea anyway.

Jk

In reply to summo:

> Would that be "scotland's" green energy paid for by a subsidy added to every household bill across the UK? 

There is no subsidy.  There are two different products: green electricity and fossil fuel electricity.  You sign up to the climate accords and you need to buy green electricity which means you need to pay the price for green electricity.

5
In reply to tom_in_edinburgh:

> There is no subsidy.  There are two different products: green electricity and fossil fuel electricity.  You sign up to the climate accords and you need to buy green electricity which means you need to pay the price for green electricity.

Of course there are, green levies have been added to all uk bills for years, they subsidise investment in research in new sources, such as tidal off the orkneys, and also subsidise various production of energy. You chunter on about everyone having to pay for Scottish renewable energy, but don't have a clue who funded it in the first place. So next time when sturgeon is claiming how green Scotland is, just remember that green energy is as much a London residents as yours. 

https://www.ft.com/content/4b59d4da-2f29-4bda-8031-d20d0503cad0

Post edited at 05:47
2
In reply to summo:

In exactly the same way as the resources the English stole from India were a London resident's as much as an Indians before India became independent.

After independence it is a different deal.  We will extract the maximum price the market will bear and we won't give a flying f*ck about what regulators in London think.

14
 Andy Hardy 05 Oct 2021
In reply to tom_in_edinburgh:

If every Scot backing independence thinks along the same lines as you do, independence is going to go much worse than brexit. For all of us.

In reply to jkarran:

Tidal lagoons will clip/square the sinusoidal shape of the tidal range, how much and exactly how depend on the scheme's design and operation. Likely it is the lowest tide in the lagoon that is most affected/squared and there's a belief that this is the biggest environmental impact especially to birds. During the lowest point in the tide, mudflats and sandbanks get exposed that are highly valuable feeding sites for many species. Let's say the RSPB aren't super keen on the proposed Severn schemes! but their campaign message doesn't (in my view) articulate exactly *why* they think it is so bad, it just assumes barrage=bad without enough explanation

https://www.rspb.org.uk/our-work/casework/cases/severn-estuary/

In reply to tom_in_edinburgh:

> In exactly the same way as the resources the English stole from India were a London resident's as much as an Indians before India became independent.

Hardly, uk wide consumers have and are subsidising renewable energy production across the Uk. This has absolutely nothing to do with Westminster taking something from Scotland, if anything it's money flowing into Scotland. 

2
 jkarran 05 Oct 2021
In reply to CantClimbTom:

I read the paper you linked, the message on impact is very mixed and a little uncertain. At La Rance it seems the worst of it stemmed from now obsolete construction techniques and while the site isn't especially similar to the Severn, having steeper banks so less tidal flats, the ecological recovery appears to have been very good (with some caveats about poor baseline studies and generally changing environments making a direct before-after comparison difficult). Habitats have changed and moved but biodiversity recovered very well overall after the shock of construction and with improvements over the years as the management strategy evolved (switching to bi-directional generation and minimising interruptions to 'normal' tidal cycles).

As I said, I suspect it's a moot point since there'll be enough objections (justified and/or not), protest and a big enough economic barrier that it never happens anyway.

The paper does raise the interesting idea of a less dramatic and potentially less impactful but comparably powerful submerged tidal bar in the Severn. There though you're into the realm of purely theoretical impact simulation with no case studies for calibration.

jk

 Si dH 05 Oct 2021
In reply to CantClimbTom jkarran and mbh:

> The issue is more what would be the impact to Severn Estuary or Wherever a proposed scheme is, rather than what happened at La Rance as each site is individual.

The report I linked higher up the thread went in to the predicted environmental impacts of the Severn barrage options. There were some striking numbers on things like impacts on local fish populations. That's why I said in my earlier post that I'd like to see to tidal power contributing to our needs if the environmental impacts can be mitigated. Not otherwise. It's definitely an important consideration.

In reply to summo:

> Hardly, uk wide consumers have and are subsidising renewable energy production across the Uk. This has absolutely nothing to do with Westminster taking something from Scotland, if anything it's money flowing into Scotland. 

Money flowed into India too.  Just nothing like enough money to fairly compensate the Indians for what was extracted.

7
 Phil79 05 Oct 2021
In reply to mbh:

> David Mackay's seminal book 'Sustainability without the hot air' from a decade ago put it well, using back of the envelope calculations that any numerate person can grasp. He shows that, if fully exploited, the whole of tidal power generation in the UK,  not just the Severn, would generate about 4 kWh per person per day, whereas we use somewhere between 100 and 200 kWh per person per day, depending on where you draw the line.

This is a great read, really useful for your getting head around the basics of 'how much' and 'where from' etc. Still free to read here:

https://www.withouthotair.com/

In reply to tom_in_edinburgh:

With Indian colonialism, they didn't have representation in Westminster, partly "thanks" to Winston Churchill's vigorous campaigning to prevent them having any voice/representation self governance or anything of that nature.

However 59/650 of the MPs in Westminster (about 9%) represent constituents in Scotland compared to Scotland being 5.5M/67M (roughly 8%) of UK population.

So IMHO to compare a population represented by elected members with oppressed India does nothing other than emotively misleads debates on whether Scotland is represented as well as it could be - and is definitely an unhelpful distraction from the serious debate of electricity generation/distribution and the environment, tidal or otherwise

May I suggest you form a different thread, to debate Scott Nat issues rather than continue to derail this one

 Si dH 05 Oct 2021
In reply to tom_in_edinburgh:

Drawing parallels between colonialism in India and the relationship between England and Scotland in the 21st century is just f*cking ridiculous.

In reply to tom_in_edinburgh:

> In exactly the same way as the resources the English stole from India were a London resident's as much as an Indians before India became independent.

Oh 100% exactly. The victims at Amritsar would have really seen you as brave, oppressed brothers in arms.

> After independence it is a different deal.  We will extract the maximum price the market will bear and we won't give a flying f*ck about what regulators in London think.

Yes, you'll find that is just the market price. You're not talking about being the only available supplier of something like natural gas here. England/Wales has interconnectors with France (2), Belgium, Netherlands and Norway, with one with Ireland coming soon and potential for another two to France. We'll just open the circuit breakers and your expensive new generation assets will sit idle.

Glad to see your as good at diplomacy as you are understanding the energy markets and network operation.

In reply to CantClimbTom:

[to Tom in Scotland] May I suggest you form a different thread, to debate Scott Nat issues rather than continue to derail this one

Seconded. 

 rka 05 Oct 2021
In reply to rsc:

Grid constraints are a real problem in scotland Rgen/SSEN are holding a webinar about there plans next week.

https://www.regen.co.uk/event/ssen-distribution-future-energy-scenarios-north-of-scotland/

There do appear to be some easy tidal sites on west coast sea lochs - caolas nan con on Loch Leven on the way up to Kinlochleven. Easy road access, fast flow and an existing grid connection near by - 23.27 Mw export from blackwater scheme.

In reply to rka:

Now if you could spot a few sites suitable for tidal generation close to potential pumped storage schemes, you'd be picking winners!

In reply to MonkeyPuzzle:

Look at the transmission system charges in the rest of Europe.  The English are taking the p*ss out of Scotland.  It is f*cking amazing what they get away with.

https://twitter.com/NickyZog/status/1446021713473548289/photo/1

6
In reply to tom_in_edinburgh:

It's still based on the distance between generation and demand due to the transmission losses in between. 

In reply to MonkeyPuzzle:

> It's still based on the distance between generation and demand due to the transmission losses in between. 

I'm sure that decision makers living in London think it is all entirely fair.   I'm equally sure that decision makers living in Scotland after independence will have a different perspective.

9
In reply to tom_in_edinburgh:

> I'm sure that decision makers living in London think it is all entirely fair.   I'm equally sure that decision makers living in Scotland after independence will have a different perspective.

Tom, on behalf of myself and others in London, please let me apologise for Scotland's dispersed population and hilly) rural/hilly terrain especially the Highlands.

Now.. can we discuss tidal power again please?

1
In reply to CantClimbTom:

> Tom, on behalf of myself and others in London, please let me apologise for Scotland's dispersed population and hilly) rural/hilly terrain especially the Highlands.

Yeah, the hilly terrain would explain why Scotland are charged 5x higher feed in tariffs than Norway.

> Now.. can we discuss tidal power again please?

We are discussing tidal power.  Look at how many EU countries have zero tariffs to shift the cost to the consumer rather than the supplier and encourage renewables.  The UK pushes the cost  of the transmission network on the supplier and because of the ridiculous level of economic centralisation in SE England ends up with most consumption in one corner of the country and the generation in another.   SE England should pay for that and the cost should be an incentive for people and businesses to move to other regions.  Won't happen because the decision makers live in London.

5
 wintertree 08 Oct 2021
In reply to tom_in_edinburgh:

The answer is probably to built the first generation of commercial fusion plants around London and just stop buying Scottish renewables.  

With ohmic losses, it's fundamentally stupid to have a lot of generation far from the people, and your usual approach Tom is that magic future technology will solve everything, so let's get some magic future technology to allow people to keep living in high density in the South East as they so desire rather than expecting millions of people to up-root and move to somewhere that they don't want to go, or to pay higher prices.

However, and of relevance to the thread, I think that commercial scale fusion reactors aren't looking so much like magic future technology any longer.

There's been a seismic shift in the achievements and investment levels in the non-academic, non-giant-tokamak world in the last few years.  Private investment in Tri-Alpha (now TAE) is over $1 Bn now, the MIT spin out Commonwealth Fusion Systems apparently had $ 1 Bn of investment lined up if their prototype superconducting coil passed validation, which it recently did (big news in small circles). Tokamak energy are raising serious funding in the UK.  There are many other firms making significant progress.

The problem with ITER was and remains that it's too large - physically, institutionally and energetically (in terms of power output per unit area of the vacuum vessel).  It's going to end up like the superconducting super collider, except no good for mushroom farming.  ITER hopes to solve the complex problems of the plasma boundary interface turbulent behaviour and of leaky confinement in a finite chamber with sheer scale, and that scale has brought so many hard problems; the new generation of compact reactors solve those problem in other ways with different confinement modes and different field geometries, and in so doing keep the output power densities (and neutron flux...) at levels we know how to handle, and keep the scales of financing and project managing commercial reactors to a believable level that is compatible with past achievements.     

The way investors approach transformative physics driven, control system heavy technology has had its own seismic shift following SpaceX I think, who showed quite clearly that the lack of progress from highly funded incumbent firms over the last 40 years in a different field - also conventionally seems as ultra-difficult - was in large part cultural and management issue as much as anything to do with the physics or engineering.  (Well, there had been progress with e.g. the DC/DC-X.  Pork barrel politics killed that.)

We'd still be fools to bet the house on fusion coming through, but the odds are changing, as are the probable timescales, and whilst I can't see an ITER/DEMO derived power plant undercutting a renewable future on cost, I'm a lot more optimistic about commercial fusion with more compact reactors.

 StuPoo2 08 Oct 2021
In reply to tom_in_edinburgh:

From one fellow Scot to another (I assume) - your posts are so often such a awful example of the Independence movement in Scotland.

Why can you not invest your significant posting efforts to advance the positives of Independence rather than so much emphasis spent on the anti-English grievance theme all the time?

In a thread about bloody tidal power you have successfully made the case for how a newly independent Scotland would strive to hold its neighbor ransom to its plentiful green energy.  What an absolutely bizarre and utterly negative spin to have put on this.    

Re: Pricing Power

You might actually be right ... a newly independent Scotland might have some pricing power over its green energy in the short term but at the exact same time England and the rest of the world will have some pricing power of other products in Scotland.  I will bet $100 that the external bigger parties have a greater amount of pricing power over Scotland than any newly independent Scotland has over the rest of the world.  More to the point ... a newly independent Scotland would not strive to price gouge anyone - that's just Tom/SNP grievance talking.    Scotland isn't the grievance carrying country to make it out to be - its a positive, inclusive 21st century modern economy. 

It also goes without saying that England would not lay down and decide to accept a situation where it was paying a premium for its power ... it will inevitably invest in cheaper power sources that it doesn't have to pay Tom's Anti-English Green Power Premium fee for.  Any pricing power Scotland did have would disappear over time.

Re:  Transmission Distance

Whether you like it or not the further the energy needs to travel ... the more it costs to get it there - C'est La Vie ... that's present whether Scotland is independent or not.  If you need to pipe it under the sea its going to increase the cost per unit.  

You are exactly the type of grievance carrying independence supporter that I loath.  

Post positively about Independence.  Price gouging our neighbor for green power is 100% not a positive of Independence. 

#SpreadIndependenceNotHate

1
In reply to tom_in_edinburgh:

> I'm sure that decision makers living in London think it is all entirely fair.   I'm equally sure that decision makers living in Scotland after independence will have a different perspective.

Both Ohm's and Watt's Laws think it's entirely fair, so you'll have to take it up with them.

In reply to StuPoo2:

I think most of us are convinced by now that TiE is actually a satirical comedy character created and operated by Alistair Darling, so no need to be too concerned.

In reply to MonkeyPuzzle:

> Both Ohm's and Watt's Laws think it's entirely fair, so you'll have to take it up with them.

It's nothing to do with Ohms law or Watt's law.  It is political

Somebody has to pay for the cost of moving electricity over long distances - although newer technologies can reduce that.

You can decide the supplier far from the population centres should pay extra OR you can decide that electricity consumers should pay more the further they are from the power generation.

If you make the generators pay then you discourage renewable investment further from SE England.  If you make the consumers pay you encourage large energy consumers to move closer to the supply and give people an economic incentive to move away from SE England.

The central problem of the UK is that everything is incentivised to move closer to London.  The pricing structure for energy is another example of this.  Green electricity in London should cost a f*ckton more than it does in Edinburgh, and it should cost more in Edinburgh than it does in Skye or Kinlochleven or Inverness.  But you go to Kinlochleven and houses within 200m of a hydro power station are burning coal because it is cheaper than electricity.  Running electric vehicles in the Highlands or on Skye should be pretty much free because quite often the grid can't even accept all the wind power that's being generated.    The whole problem is caused by people in London making the decisions on energy strategy for the benefit of consumers in London.  

11
In reply to StuPoo2:

> From one fellow Scot to another (I assume) - your posts are so often such a awful example of the Independence movement in Scotland.

> You might actually be right ... a newly independent Scotland might have some pricing power over its green energy in the short term but at the exact same time England and the rest of the world will have some pricing power of other products in Scotland. 

Pricing power is always temporary, you need to use it when you've got it.  That's not hate it is business.  Very likely 20 or 30 years out nuclear fusion will start to make wind farms redundant.  So we make our money from what we have while we can, then we move on to the next thing.

The market price for electricity exported to England is determined by the next most competitive supplier and the ratio of supply to demand.   English windfarms are always going to be more expensive because land is more expensive.    It should be an arms length relationship where we attempt to extract the economic value of our resource rather than do favours for the English.

The technology for interconnectors across the North Sea is already there.  That's another factor which will influence pricing because it gives us another potential customer base who are also required by climate laws to purchase green energy.

The part about the 'rest of the world' is nonsense.  Scotland needs to get back into the EU and trade in that much larger market to become less dependent on England.  Once we are in the EU we can buy anything we can buy from England from EU suppliers.  It's not going to be England saying 'if you charge more for your electricity we'll charge more for our <whatever>' because we will say OK then its cheaper and better from the supplier in the EU anyway.  Bye.

Post edited at 22:32
7
In reply to MonkeyPuzzle:

Shit...how could I have gone so long not realising Tom is a superNATtroll! 

1
 fred99 09 Oct 2021
In reply to tom_in_edinburgh:

> I'm sure that decision makers living in Glasgow/Edinburgh after independence will think it is all entirely fair.   I'm equally sure that decision makers living in the Highlands after independence will have a different perspective.

Fixed that for you.

In reply to wintertree:

There's been a seismic shift in the achievements and investment levels in the non-academic, non-giant-tokamak world in the last few years. 
 

That’s a metaphor I don’t want anywhere near fusion power.

Sorry. Now I’ll go and make a proper effort to understand your post.

 Kalna_kaza 09 Oct 2021
In reply to tom_in_edinburgh:

European electrical generation is highly integrated, it's simply not a case of "we export more than we generate". Once Torness and Hunterston B go offline Scotland simply doesn't have any base load low carbon power generation of its own. There is little or no chance of this being replaced. Come a cold, windless night Scotland either a) burns gas b) imports electricity from elsewhere or c) turns out the lights.

Energy supplies are of strategic importance but very few countries are truely independent. 

To get back on topic, it would be great to see tidal being a much bigger part of the energy mix.

1
 wintertree 09 Oct 2021
In reply to rsc:

> That’s a metaphor I don’t want anywhere near fusion power.

Fusion is way safer than fission when it comes to natural disasters, terrorists, operator gross incompetence, air crashes and the like.  There's a bit of tritium (For now...) and the pressure vessel lining could get a bit radioactive, but there's no ability to have a criticality or explosion spreading vast amounts of fallout.

> Sorry. Now I’ll go and make a proper effort to understand your post.

I might just be testing your anti-bluffing instinct alluded to above

On the energy and magic future technology front, the unbelievably insane drop in $/kg to orbit that SpaceX's Starship should deliver (*) should make space based solar power viable - this is satellites in permanent sunlight fixed in position above locations on the earth in geostationary orbit beaming power by microwave to receiving farms on earth.  

A 2 km diameter array in orbit could beam 6 Gw to a receiving station 600 m in diameter, with a fail safe delivery system that can't wander off target.  The receiving station is a field full of little more than metal aerials with some diode bridges on them.  (For a 10 km diameter orbital array, that becomes 150 Gw and a 120 m diameter receiving station)

Solar power 24x7 with no atmospheric losses, no clouds, no night, no weather.

The main barriers to a realistic system have been the cost to orbit and the problem of dealing with ohmic losses in space where cooling is very, very difficult if you make a lot of heat.  SpaceX and modern high temperature superconductors change this.  Even the UK is getting in on the act with some UKSA and MOD research underway.

(*) Starship is the beginning of the proper space age, not the end of it.  Wait till they scale it up, again.  Also, create enough demand for materials in orbit and the business case will emerge for non-rocket space launch such as the Gerard Bull / Iraqi Supergun style launchers. It only takes something like £6 worth of energy to put 100 kg in orbit if you do it with a space gun.  All the metal for the truss work for a power plant can go up this way, and potentially raw materials for orbital factories for solar-PV cells and HTS cable.

The very real problem is keeping the wheels on society and high technology for the next 25 years so that all this magic future technology can become real; for that we need to spend as much on renewables as we can, as rapidly as we can.

 wintertree 09 Oct 2021
In reply to tom_in_edinburgh:

> Once we are in the EU we can buy anything we can buy from England from EU suppliers.   It's not going to be England saying 'if you charge more for your electricity we'll charge more for our <whatever>' because we will say OK then its cheaper and better from the supplier in the EU anyway.

I'm pretty sure you should understand Ohms law, and that you have access to a map.

Also, how the flying **** is EU electricity "better" than English electricity?  Enquiring minds want to know.

 Kalna_kaza 09 Oct 2021
In reply to wintertree:

> I'm pretty sure you should understand Ohms law, and that you have access to a map.

> Also, how the flying **** is EU electricity "better" than English electricity?  Enquiring minds want to know.

Indeed, for prolonged periods a good chunk of EU electricity is has a larger carbon footprint than that of the UK. France is the major exception whilst Germany will regress into higher CO2 emissions due to nuclear phase out and Nordstream 2 coming online with Russian gas. 

https://app.electricitymap.org/map helps underline my previous post regards interconnectivity. Poland and Estonia are regularly the most polluting per KWh. Ireland still has peat(!!!) powered plants. 

Norway looks pretty smug with its low population and amazing geography suited to hydro power.

In reply to wintertree:

> > Once we are in the EU we can buy anything we can buy from England from EU suppliers.   It's not going to be England saying 'if you charge more for your electricity we'll charge more for our <whatever>' because we will say OK then its cheaper and better from the supplier in the EU anyway.

> Also, how the flying **** is EU electricity "better" than English electricity?  Enquiring minds want to know.

My comment wasn't about electricity it was in response to a post that said if Scotland increased the price of electricity then England had the power in the relationship because there are far more things it could increase the price of.   When Scotland is back in the EU there are very few things where buying from England would be a better option than buying from the EU.

The whole 'England has the power' is a central fallacy of Brexit.  England has very little power over EU member states.  It doesn't have power over Ireland and it wouldn't have power over Scotland.

5
In reply to Kalna_kaza:

> European electrical generation is highly integrated, it's simply not a case of "we export more than we generate". Once Torness and Hunterston B go offline Scotland simply doesn't have any base load low carbon power generation of its own. There is little or no chance of this being replaced. Come a cold, windless night Scotland either a) burns gas b) imports electricity from elsewhere or c) turns out the lights.

Scotland isn't short of gas.  Plenty of the stuff comes into Mosmorran from the North Sea.  

If they build the Scotland-Norway interconnector that will help too.

3
 mik82 10 Oct 2021
In reply to wintertree:

> Also, how the flying **** is EU electricity "better" than English electricity?  Enquiring minds want to know

English electricity is heavier and more dangerous

youtube.com/watch?v=cOzwS0rN5z8&

 Maggot 11 Oct 2021
In reply to tom_in_edinburgh:

> If they build the Scotland-Norway interconnector that will help too.

Shame, looks like we've already got one...

https://www.euronews.com/2021/10/01/north-sea-link-world-s-longest-undersea-power-cable-linking-norway-and-uk-is-now-operation

It'll be a while before you get yours 😄😄😄

1
 Harry Jarvis 11 Oct 2021
In reply to tom_in_edinburgh:

> My comment wasn't about electricity it was in response to a post that said if Scotland increased the price of electricity then England had the power in the relationship because there are far more things it could increase the price of.   When Scotland is back in the EU there are very few things where buying from England would be a better option than buying from the EU.

The only current route for importing electricity into Scotland is through England. This won't change  with independence. In the event of an interconnector being built, either to Norway or the EU, one would hope that an independent Scotland would buy at the best price available, regardless of its origin. Given the vagaries of the electricity markets, this will probably vary from England, the EU and Norway at different times and different demands. 

Basing an energy policy on a notional membership of the EU which will not happen for many years does not seem a sensible proposition. 

In reply to mik82:

> English electricity is heavier and more dangerous

If you microwave a haggis in England it will just explode and it tastes offal.

The same microwave, powered by Scottish electricity, will transform it into a steaming brown pile of Caledonian ambrosia.

 robhorton 11 Oct 2021
In reply to henwardian:

> 1) The sites for effective power generation are very limited.

This is my issue with tidal generation. There's an application going through for a demonstration area off Holyhead (Morlais Scheme) which would generate around 240MW. That's a decent amount of power but given the proposed new build nuclear stations would be around 3GW, even if there is no direct adverse impact on the birds / sealife I really wonder if it's worth it. The great thing about wind power is you can plonk some turbines in a field in Bedfordshire without upsetting anyone but strong tidal flows tend to be in "special" places which I think we should be a bit more reluctant to industrialise.

1
In reply to robhorton:

Looking at the Bristol Channel from Burnham to Weston to Avonmouth, I think there's a strong argument to just concrete over and start again regardless of any gain to the country's energy supply.

 fred99 11 Oct 2021
In reply to robhorton:

> ....The great thing about wind power is you can plonk some turbines in a field in Bedfordshire without upsetting anyone ....

Says someone who, according to his profile, lives in London. *

Obviously having some dirty great windmills in Bedfordshire won't upset YOU, but why should people who live in Bedfordshire have to live with them.

Isn't it about time that these turbines were located right close to where the electricity is consumed - such as adjacent to the M25 or even within it !!

People say there's no wind in London (?) , but surely every single hill could be utilised rather than continually wanting to desecrate the countryside.

* The same goes for other metropolitan areas that want to ruin nearby countryside. Townies complaining about rural communities being "nimbys" is pretty rich considering where all this electricity is consumed.

 robhorton 11 Oct 2021
In reply to fred99:

Blimey, I didn't realise the arable fields of Bedfordshire were so loved by the people of Bristol.

My profile also still says I'm 30...

 Harry Jarvis 11 Oct 2021
In reply to fred99:

> Says someone who, according to his profile, lives in London. *

> Obviously having some dirty great windmills in Bedfordshire won't upset YOU, but why should people who live in Bedfordshire have to live with them.

Don't people in Bedfordshire use electricity? 

In reply to fred99:

> Says someone who, according to his profile, lives in London. *

> Obviously having some dirty great windmills in Bedfordshire won't upset YOU, but why should people who live in Bedfordshire have to live with them.

> Isn't it about time that these turbines were located right close to where the electricity is consumed - such as adjacent to the M25 or even within it !!

> People say there's no wind in London (?) , but surely every single hill could be utilised rather than continually wanting to desecrate the countryside.

> * The same goes for other metropolitan areas that want to ruin nearby countryside. Townies complaining about rural communities being "nimbys" is pretty rich considering where all this electricity is consumed.

The ethics of piling more and more industrial infrastructure into the same areas to preserve the rural house prices of well-off retirees are shaky I'd say. Not that we don't spend literally 100s of millions of pounds not only already doing that but actually burying existing transmission circuits (See Dorset and other "VIP" (visual impact provision) schemes). But sure, the cities should look like Bladerunner and everywhere else like Hobbiton.

In reply to fred99:

Urban environments are terrible places for wind turbines. The buildings slow down and stir up the wind. 

Economics dictates that wind farms are best put where it is windy, since twice the wind speed means eight times as much power. 

That is the main driver for making wind turbines taller - less drag on wind from the ground, so more wind - and one of the reasons for putting them out to sea, despite the additional cost -  the sea puts up less drag on the wind.

 fred99 11 Oct 2021
In reply to Harry Jarvis:

> Don't people in Bedfordshire use electricity? 

I think the main source of my gripe was that the poster stated "strong tidal flows tend to be in "special" places which I think we should be a bit more reluctant to industrialise."

So why choose to industrialise somewhere else, just because it's not so pretty - in their eyes.

The other matter is simple - why on earth are so many people ramming themselves into a part of the country that has within itself no source of power, no source of water, no source of food, etc.. The amount of electrical energy lost in getting from source is criminal, as are the resources expended to get everything else required for life into this one corner of the country - for which I do agree with TinH, in that its' inhabitants do think that it's the centre of the universe.

Am I not alone in remembering that a few years ago there was a move to drown a valley in Northamptonshire to provide a further reservoir for London - at a time when the water supply system was losing up to 40% down the drains due to leaks in the system.

1
 wintertree 11 Oct 2021
In reply to thread:

I’ve been trying to find the description - with pictures - of bringing a plant in to sync with the (then regional) grid, which I’m sure is in my copy of the Children’s Encyclopaedia.  No joy, but I did find some prescient pre-war pontification on renewables and the “reign of coal perhaps drawing to a close” from Arthur Mee, and a photograph with a timely (or timeless…) caption from Newnes Pictorial Knowledge.


In reply to Harry Jarvis:

> The only current route for importing electricity into Scotland is through England.

We already get 95.9% of our electricity from 11.9 GW of renewables.  The rest is from nuclear and gas, and we have plenty of gas from the North Sea.  We have more than the same again in renewable energy capacity 14.6GW already in the pipeline.   We are already an energy exporter, add in the new wind in planning and construction and the new Cambo oil field and we are laughing.

https://www.gov.scot/binaries/content/documents/govscot/publications/statistics/2018/10/quarterly-energy-statistics-bulletins/documents/energy-statistics-summary---june-2021/energy-statistics-summary---june-2021/govscot%3Adocument/Scotland%2BEnergy%2BStats%2BQ1%2B2021.pdf

In reply to tom_in_edinburgh:

> We already get 95.9% of our electricity from 11.9 GW of renewables.  

We? Who owns them? Who funded them? 

 Harry Jarvis 12 Oct 2021
In reply to tom_in_edinburgh:

> We already get 95.9% of our electricity from 11.9 GW of renewables.  The rest is from nuclear and gas, and we have plenty of gas from the North Sea.  We have more than the same again in renewable energy capacity 14.6GW already in the pipeline.   We are already an energy exporter, add in the new wind in planning and construction and the new Cambo oil field and we are laughing.

As has been pointed out, wind is an intermittent source, and when the wind doesn't blow, we need base-load generation from either nuclear or gas. Torness is due to be decommissioned in 2030 and Hunterston is entering its decommissioning phase. New gas-fired generation is not compatible with the Scottish Government's goals to decarbonise Scottish energy. 

We should not be laughing. We are in a very difficult place, and although Scotland is better placed than many countries to meet the challenges of a low-carbon economy, we have a long way to go. Your flippancy is similar to that of the Brexiteers who assured us of easy post-Brexit trading. 

In reply to summo:

> We? Who owns them? Who funded them? 

As a sovereign state Scotland will benefit from them just like any other state with oil or gas or wind.   The Westminster rules paid for by Tory donors will be over.  Maybe some landowners with huge windfarms on their land won't get paid or taxed so hard the money comes back.   Cry me a river.

3
In reply to Harry Jarvis:

>  New gas-fired generation is not compatible with the Scottish Government's goals to decarbonise Scottish energy. 

When push comes to shove if you need a bit of gas generation and you have plenty of gas then you build a bit of gas generation.  With so much renewable Scotland will be way ahead on any carbon targets set by COP.  It is the UK that has a problem meeting them because England is packed full of people and industry.

2
 Harry Jarvis 12 Oct 2021
In reply to tom_in_edinburgh:

> When push comes to shove if you need a bit of gas generation and you have plenty of gas then you build a bit of gas generation.  With so much renewable Scotland will be way ahead on any carbon targets set by COP.  

Renewable electricity accounts for about one third of Scotland's existing energy needs. Even with the planned expansion of wind, we are not way ahead. We will still be some way behind. 

In reply to Harry Jarvis:

> Renewable electricity accounts for about one third of Scotland's existing energy needs. Even with the planned expansion of wind, we are not way ahead. We will still be some way behind. 

Jesus.  We get to 95.8% renewable electricity and are building more than the same again and you say we are behind.

We are miles ahead of England, the UK as a whole and it is hard to think of more than a handful of other countries in the developed world that could come close.  

It's ridiculous the way unionists and the English media talk Scotland down.   It is an intetnional tactic because if we recognise how good we actually are and get some self confidence we'd leave.

6
 Harry Jarvis 12 Oct 2021
In reply to tom_in_edinburgh:

> Jesus.  We get to 95.8% renewable electricity and are building more than the same again and you say we are behind.

I've done a little more reading, and I'll admit I was wrong. In 2019, renewable electricity accounted for 23.9% of Scotland's total energy consumption. We have a long way to go. 

https://scotland.shinyapps.io/sg-scottish-energy-statistics/?Section=WholeSystem&Chart=RenEnTgt

In reply to tom_in_edinburgh:

> Jesus.  We get to 95.8% renewable electricity and are building more than the same again and you say we are behind.

> We are miles ahead of England, the UK as a whole 

There is no Scottish 'we'. They aren't owned by the snp. Most are owned privately. They've been built with money subsidised by the green levies added to ALL uk household bills, many sources are subsidised by the uk treasury which receives its funds from ALL parts of the UK. The wind might blow across Scottish hills, but those midge laiden particles of air are the only part of the system which can be even remotely described as Scottish. 

 AJM 12 Oct 2021
In reply to tom_in_edinburgh:

> Jesus.  We get to 95.8% renewable electricity and are building more than the same again and you say we are behind.

I feel like there's a few things you could infer from the idea that you've apparently got nearly complete renewable generation and are planning on doubling it still:

- the 95.8% is wrong, or represents peak rather than sustainable proportion

- that lots of people are building renewable generation capacity for export (95.9% if true means no demand in Scotland for another 100%, doesn't it, so it must be for export) now despite these cripplingly high connection fees you've been grumbling about i.e. they're not really crippling after all and still allow companies to make decent return

- that lots of people are building renewable energy capacity for export on the premise that whilst it might be loss making now one day they'll be able to turn a profit on it as the interconnect fees plummet in a post independence future.

 ScraggyGoat 13 Oct 2021
In reply to summo:

Agree, see Parkwatch blog for run of the river hydro, highlighting that the main flow is cash out of Scotland and the UK, into offshore entities;

http://parkswatchscotland.co.uk/2021/10/12/green-hydro-wash-the-planning-application-to-extend-the-ben-glas-hydro-scheme-by-loch-lomond/
 

Before Tom blames Westminster, let’s remember the SNP have bent over backwards to help such schemes, calling in planning applications, redefining wild land areas, while knowing most schemes profits would be offshored.  All the while having the legislative power to change this.

When the SNP came to power the Scottish landed elite thought they were having a nightmare, but in reality the SNP is now their wet dream.

 GForce1 13 Oct 2021
In reply to tom_in_edinburgh:

'England doesn't have enough power and committed to green energy.  Take away Scotland and your lights go out.'

I'm sorry that is simply not true. It's England that keeps Scotland's lights on. It's Scotland not England that has limited and no plans to replace it's dispatchable power.

There's nothing particularly noble about the SNPs energy policy, hiding behind 'equivalent' figures, claiming to have de carbonised the power industry, whilst ignoring the vast amounts of carbon generated from gas stations south of the border. What they are doing is encouraging the building of a generation system that is not fit for purpose and lining the pockets of multi-nationals and dodgy investments. We need to take planning away from the politicians and give it back to engineers. They have given us a grid completely reliant on gas.

And for information I live/work in Scotland and have been involved in the design of new build renewable projects and have seen the questionable way schemes are justified.

Post edited at 22:12
 GrahamD 14 Oct 2021
In reply to GForce1:

You can't give power like that to unelected experts !

In reply to rsc:

At least the tidal power stations don't look like badly drawn willies

https://www.bbc.co.uk/news/uk-england-cumbria-58911210

 cb294 15 Oct 2021
In reply to tlouth7:

> An issue with nuclear is that we price in the cost of mitigating the big dangers (meltdown, fallout etc), whereas for fossil fuels we don't (carbon emissions leading to, well, the apocalypse).

This, times 1000!

People got scared by Tchernobyl and later Fukushima, but emissions from coal power already directly killed more people per kWh than nuclear, and climate change will kill orders of magnitudes more.

And that is not even including the large scale wars we can expect over resources like water (Syria was arguably an early example) or dry land (what will happen once half of, say, Bangladesh will become uninhabitable, either through direct flooding or destruction of agriculture by salt water influx).

CB


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