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Heat Source Air Pump, Worth A Crack?

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 Tall Oak 30 Oct 2020

Hello folks.

I am a late bloomer to this, but trying to get more of general perspective on ground / air source heat pumps.

Questions are:

I read that there is a Renewable Heat Incentive (RHI) for every heat kWh that is produced the user is paid for this? The sums I saw were for a feedback for seven years. Is this true? if a kit costs roughly 11k, then once could earn, according to the sales advert, £2.2k a year for seven years? 

If the above is true, then how is this metered and who pays this cheque to the consumer for every kWh produced?

There is paradox for me (trained as an engineer) where, roughly speaking, 1kWh electrical power produces 3kWh of heat energy. My science teacher was emphatic that there is no power conversion (electrical, heat... etc) that is better than 1 in the universe. It smells fishy and yet every video I see on the named video channel most use states this. H

Any environmental issues to call of? In that the chemical compound used is not water and boils at a much lower temperature within the heat exchanger. 

Mucho gracias

 jimtitt 30 Oct 2020
In reply to Tall Oak:

1kWh extracts 3kWh energy from the air, the sun produced the energy (converted it is more correct).

 nikoid 30 Oct 2020
In reply to Tall Oak:

In your example you really do end up with 4kW of heat into your house for every kW of power drawn from the grid. The coefficient of performance is 4 in this case. It is like a fridge the other way round. But like you I'm still a bit baffled by the thermodynamics. I'm sure some physicists will be along soon....

 henwardian 30 Oct 2020
In reply to Tall Oak:

It is powering a pump for heat. So it is taking 1kWh of energy running the pump to transport 3kWh of heat energy from the outside inside. It essentially works like a reverse fridge.

If the temperature outside is too low the system will not work at all (but you probably don't have to worry about that ever happening in the UK).

The gas used for this sort of thing used to be CFCs which were bad (ozone depletion, etc.) but is now something else which doesn't cause ozone damage or have (known) nasty effects.

I'll watch this thread with interest because I'm going to be building a new house and am still very undecided on how to heat it and what energy source to use.

Edit: Also the amount of subsidy you get to pay this thing off is heavily dependent on the energy efficiency of your house. So if your house is a cardboard box with holes in it then you can claim a monstrous subsidy as you will burn huge amounts of electricity running the airsource constantly at full whack. But if you have a really well insulated modern home then you expect to use it very little and consequently you will get a lot less money back. Which is all rather silly when you consider that the point of the subsidy is to encourage energy efficient practice!!

Post edited at 19:33
 John2 30 Oct 2020
In reply to Tall Oak:

I believe some people are not happy with the amount of noise from the pump.

2
 Subseaeng 30 Oct 2020
In reply to Tall Oak:

We have had an ASHP installed now since 2009 and are generally happy with it. We are in a rural location and were on oil and no gas available. If you have mains gas available then an ASHP is (in my opinion) not viable.

Be very aware of the RHI and the numbers quoted. I think all these salesmen are charlatans. You will need an Energy Performance Certificate (EPC) from an EPC surveyor after the ASHP is installed (another scam). I think that you will only get anywhere near that figure of £2.2k if you have an EPC rating of A or better, eg our house has an EPC of D (and we think it isn't bad) and we get about £600/yr (now in our 7th and last year). I think to get an A the house needs to be exceptionally well insulated on floors, walls, windows/doors and roofs, and if it is that good then a camping gas stove will be enough heating anyway.

You have to confirm a declaration every year that the RHI is still applicable, we do not have to submit readings but there is always a possibility that you may have to.

If you have more questions then I am happy to give you our experiences but better to do that via email. Iain

 henwardian 30 Oct 2020
In reply to nikoid:

> In your example you really do end up with 4kW of heat into your house for every kW of power drawn from the grid. The coefficient of performance is 4 in this case. It is like a fridge the other way round. But like you I'm still a bit baffled by the thermodynamics. I'm sure some physicists will be along soon....

They key concepts are latent heat of vaporisation and phase diagrams.

Essentially if you compress a gas, it turns into a liquid when you reach a high enough pressure (there are exceptions though), there is a huge amount of energy released when this happens - released as heat - because you are basically removing a lot of the kinetic energy of the particles in the substance.

Now if you release the pressure again, the liquid you had will now boil back into a gas, this process is the reverse and so in involves a lot of energy being absorbed to give all the particles enough energy to get into the gas state.

Ground/air source heat pumps work by releasing the pressure outside, so energy from the ground/air is used to boil the substance inside the system. They then transport the gas inside, compress it and the energy it absorbed outside gets released inside your house.

The substance inside the system has to be picked so that the pressures and temperatures this system works at are effective and cheap for the prevailing conditions where it is being used.

 Philip 30 Oct 2020
In reply to Tall Oak:

I've had one for 6 years, 1 year left on the RHI.

House had no central heating. Oil was going to be ~£9k and ~£1500/year in fuel.

I installed ASHP, Solar PV and Solar Thermal. It's paid itself back Vs oil already.

The RHI payment is based on calculation not actual (metered). For my house I get ~£1200 / year heating about 280m². My total electricity bill is £1k /year and that includes cooking and family of 4.

The system is fantastic, house has a steady temperature all year. We never need the log burner. I installed radiators 4x the size for gas CH, and the system runs between 20 and 45 C depending on weather over 24hrs.

 Philip 30 Oct 2020
In reply to Subseaeng:

Actually you need a D for RHI and the payment is lowest for A. The payment is based on expected power requirement, so to maximise RHI you need a house insulated enough to pass the criteria but not so much that it reduces your heat requirement.

We got the house up from and F to D with LEDs and loft insulation. Since installing we've gone triple glazed and next year i plan to replace roof to make a huge change to the first floor and roof insulation (chalet style build). 

1
 Subseaeng 30 Oct 2020
In reply to Philip:

Ooopps. Wasn't aware it worked that way round. So how come even at D we didn't get more dosh (greedy!!)? Either way next year I'll be poorer unless they extend the RHI.

 Bacon Butty 30 Oct 2020
In reply to Tall Oak:

The BiL has one and is well pleased, but ....... he spent an absolute fortune on his house refurb.

As with PV, 5+ years ago, if you can afford to get these wonderful systems installed and reap the cashback paybacks, all well and good.

Most of this technology is out of reach for your average householder.
I would've happily received the same pence/kWh feed into grid as what I'd buy electric for, but no, pay the wealthy huge FiTs who can afford the £1000s for the installations.

It's all a wealthy privileged punters game at the moment, as can be witnessed on this thread and numerous others in the past on UKC.

We should be financing dirt cheap installations for everyone.

3
 wintertree 30 Oct 2020
In reply to Tall Oak:

The "COP" (as Nikoid & jimtit introduced) is the key specification.  It's the "Coefficient of Power" and a COP of 3 (for example) means you get 3 kW of heat out for every 1 kW of electricity put in.  The COP depends on two key factors which you'd need to investigation for your location and property to really understand how much money it'll save you.

  • External air temperature - the colder it is outside, the lower the COP so the more electrical power you have to put in.  
  • Water return temperature - the warmer the water returning to the heat pump, the lower the COP.  Typically you need giant oversized radiators, or radiators fitted with fan driven airflow, and/or underfloor heating to get the return temperature low enough to get the advertised COP.  So you probably need to upgrade to annoyingly large radiators.  LG I think do a dual cycle unit for higher temperatures.  

> Any environmental issues to call of? In that the chemical compound used is not water and boils at a much lower temperature within the heat exchanger. 

The biggest environmental issue is noise.  If you don't like noise at night, or you have nearby neighbours, an ASHP could be a source of hassle.  It's got a compressor and a bloody big fan not unlike an air-conditioning unit.  

The gas is typically a hydrocarbon I think these days (I could be wrong) that isn't a hazard to the ozone layer.

 wintertree 30 Oct 2020
In reply to Bacon Butty:

> We should be financing dirt cheap installations for everyone.

If the grid could support everyone switching to ASHPs I would agree with you...  

> I would've happily received the same pence/kWh feed into grid as what I'd buy electric for, but no, pay the wealthy huge FiTs who can afford the £1000s for the installations.

I view the FITs as a regressive tax.  As well as homeowners who can afford it, there were scum ready to exploit those who couldn't...  I had a small solar install put in just before the FITs ended and deliberately did not register for them.  

For example, "We rent your roof" firms who installed the PV panels, collect the FITs for the next 25 years and let the home owner have the power for free (if they can sue it; most being out at work during the day when the sun is out...).  When we were looking at houses I saw some atrocious jobs with mounting holes in roofs sealed with expanding foam.  The moment the FITs ended it seems the people behind these schemes sold the installations on as a job lot to money types as an investment, fired their installers and now support for the installations is farmed out almost at random.  So it's the same old same old sorts extracting profit at the expense of everyone else - those with houses encumbered with legal complications that make selling harder and damaged roofs with sub-standard installs (sometimes they go for as much roof space as they can and install too close to the edges creating wind force issues), and those paying for the FITs through their bills.

Edit:  Some of the well off folk who invested in biomass units to collect the RHI are I think starting to regret it; It's fine at 55 when you get a system without a hopper and screw-auger feed and you have to lift 20 kg to 30 kg of pellets up the feed hopper every few days, but fast forwards ten years and the pellets are no longer made from scrap wood but are in demand and expensive and those bags aren't getting any lighter...

Post edited at 21:07
 Hat Dude 30 Oct 2020
In reply to Tall Oak:

I have no idea regarding the technical figures of ASHP but I do know that some friends had a new house built to a very high standard of energy efficiency which was completed in 2010. The only heating was an ASHP; the following winter was particularly cold and they needed to add additional heating. 

 FactorXXX 30 Oct 2020
In reply to wintertree:

> The gas is typically a hydrocarbon I think these days (I could be wrong) that isn't a hazard to the ozone layer.

The gas will be a hydrofluorocarbon and even though not harmful to the ozone layer, could have a large equivalent CO2 value e.g. R410a which has a Global Warming Potential of 2088 i.e. a unit of R410a is the equivalent of 2088 units of CO2.

 veteye 30 Oct 2020
In reply to Subseaeng:

I've looked at air-source heat pumps in some degree, but there are not that many companies, as far as I've found out so far; and geographically, there are none that close to me.

I've rung a couple up, but there seem to be only certain people in each outfit, who are capable of speaking to prospective candidates for ASHP. They are not that easy to get to talk to. So consequently, as I know that my boiler is only going to last a few weeks before being dysfunctional, then I'm intending installing a gas boiler, and at some later date installing a parallel heat pump system, which I understand that you can do.

 Subseaeng 30 Oct 2020
In reply to veteye:

We were quite sceptical about being warm enough in winter despite living in SE England and we were told we could have our existing oil fired system tied in and use it as back up only when we needed it, however when the ASHP was installed suddenly we couldn't have it without some very expensive control system (what a surprise) so we canned it. We do have a nice wood burning stove which we use for a nice ambience in the lounge and obvs we do get a heat benefit as well. However having said all that if we could get mains gas we would have it in an instant. 

 henwardian 30 Oct 2020
In reply to wintertree and Wild Cyclist:

When it comes to green technology, there is a pretty well worn road where it starts out expensive, government offers subsidies to persuade mass uptake, the mass uptake drives down prices thanks to mass production and then the subsidies are withdrawn and voila: The technology has arrived, is affordable to most and making a positive difference for the planet.

The other way is to either put massive taxes on the thing you want to get rid of (i.e. regressive tax you both dislike the idea of so much) to give the thing you want to promote a competitive edge or to legislate away the thing you want to get rid of (e.g. asbestos) and this solution certainly isn't without it's problems either.

I terms of specific problems you both highlighted:

- Crappy installs are a cowboy builder/installer problem, they've got precisely nothing to do with gov legislation offering money back over time for those installation and everything to do with the building trade (and lots of other trades) having a certain percentage of cowboys, no matter what you are making/changing.

- I doubt very much that installers who got fired after FiTs expired had any trouble finding more work in an environment where solar roof installations are a burgeoning industry.

- Yup, dirt cheap installations for everyone would be nice. I don't know enough about the macroeconomics of it to endorse or argue against the idea tbh.

- The argument "people with more money can invest it and get money paid back to them and this is a problem" is a very interesting one about which much has been written. I will observe however that as far as I can see, if someone has a load of money lying around to invest, I'd much rather they were encouraged to build solar roofs, wind farms and ground-source heat-pumps to combat climate change than that they were left to invest it in apple, amazon and alphabet.

 wintertree 30 Oct 2020
In reply to henwardian:

They're all good points, thanks.  Still...

- Cowboy builders - yes the problem is in the trades, but the governments were happy to redirect all bill payer's money to builders doing sub-standard installs.  When forcing a price rise on all households it seems an abdication of responsibility to allow it to go to those cutting corners in order to profit.   Sure; this is so common now it's old news, but that doesn't make it right.

- Redeployment of installers - there was about an 18 months gap between the end of FITs and solar roofs really taking of as far as I can tell.  The very small (log store) solar roof I installed myself is falling apart after 4 years, the units were not well designed - bloody glad I didn't go large on it without a test.  Hopefully things have improved...

- Regressive taxation - the  "we rent your roof" installers profited significantly from the FITs, at the expense of all bill payers - regressively taxing those who struggle to pay their bills.  With the right financing and operating model, more installed capacity could have been achieved without the same old parasites extracting profit to their offshore havens.

- The argument "people with more money can invest it and get money paid back to them and this is a problem" - I see the logic and you're right - it's better to incentivise people to make things better than to make them worse.  My problem is more that the money to incentivise them to do so is taken from everyone, hitting hardest those least able to afford their bills.  My problem was not with the FITs but with the way they were funded.

 henwardian 31 Oct 2020
In reply to wintertree:

I think that if you are a home owner, the onus is really on you personally to decide what is and what is not a good idea for your home (unless in the unusual situation where it isn't your choice to make). You should be checking the terms, checking the work, checking the rules and basically doing your best to make sure someone isn't taking you for a ride.

If people were misled, standards were not adhered to or any other varient of fraud was perpetrated, then in my view the place to remedy that is via court or government... enquiry? I think is the way, not sure. The outcome is that people who didn't stick to the rules get their due punishment - financial or otherwise. I know this is a gross oversimplification and some people will not see justice but it is the system we have.

It sounds like people were told something a little bit too good to be true and just believed it.

I've had my fare share of failing solar pannels (flexible ones on the van roof) and been burned myself ("oh no sir, that 20 year warranty is on the cells, the construction of the panel is only warrantied for 12 months"). I'm angry about that but I accept that I just made a bad decision and got burnt.

The basic model requires private money to be invested to get public subsidies back. I can't easily see how this works if you change the system to one where private money needs to be invested but public subsidies are not going back to person/company who invests. The original FiTs were determined based on a percentage return that the government calculated would look attractive to lots of private investors, you can see this from the way the FiTs were reduced progressively as solar panels fell in price. If the public money that is set aside for this is exclusively to get solar panels on roofs then to have maximum effect, it needs to all be going to people who are paying for the solar panels. If on the other hand you want to support those who can't afford panels, you can take some of the solar roof fund and have a separate scheme where there is a means tested subsidy or lump sum given to every family who installs a solar roof. But now you have fewer solar roofs as less money is available in the original fund...

I am kind of hating you right now because I just realised replying to you like this makes me sound like a *ucking tory!

 Toerag 31 Oct 2020
In reply to Tall Oak:

No personal experience, but ground source systems need to be correctly specified - someone over here literally froze their garden due to their system being incorrectly specced.

ASHPs struggle to get their output water really hot, so are best run at al low a temperature as possible, which as stated upthread, means really big rads and/or underfloor heating.

 wintertree 31 Oct 2020
In reply to henwardian:

> I am kind of hating you right now because I just realised replying to you like this makes me sound like a *ucking tory!

Focus on my nuanced point then - my fundamental problem isn't the FITs for solar PV, but the way they were funded by adding to all electricity bills.  I can cope with subsiding the rich to get richer if it drives wider adoption of a tech that is in everyone's interests, but those in lower income brackets shouldn't have had to pay for it.  Being funded out of bills and not general taxation made it highly regressive IMO.  Further, that the "we rent your roof" profiteers and their cowboy installers were able to extract profit suggests the system wasn't set up very thoughtfully as the poorest bill payers - including those on punitive pre-pay accounts - were directly funding their profiteering.  

> The outcome is that people who didn't stick to the rules get their due punishment - financial or otherwise

Not once the firms are wound down, the ill gotten gains moved off shore and so on...

> I've had my fare share of failing solar pannels (flexible ones on the van roof) 

They're easy to change however as are normal roof mounted panels.  "Solar roof" panels overlap and are much harder to swap out.  The failures on my test samples are on the water sealing between the PV cells and the "slate effect" ground glass; this allows water ingress and fundamentally changes their appearance, if they were in a real roof it would look awful by now.

 Jamie Wakeham 31 Oct 2020
In reply to Subseaeng:

> However having said all that if we could get mains gas we would have it in an instant. 

We are nearing the point of ASHP hitting price parity with natural gas.  I'm a slightly edge case - I already have a big PV system, and wanted to fit wet underfloor heating as part of completely redesigning my ground floor, so I'm ignoring both those costs.  My gas boiler is falling apart and needs replacing anyway.  Given that, the cost of simply replacing the gas boiler versus the cost of getting ASHP, claiming RHI, and not needing to buy gas, is more or less break even in the long term.  

I agree that FiT and RHI (and EV grants) are mostly being claimed by the well off to fund expensive systems that  most people can't afford right now - but in a capitalist system I don't see how else to drive down the costs of these systems to make them affordable for all?  I have to agree they were badly managed, but they are working - PV has almost halved in price since I bought it, and would be lower still now if the moron Tories hadn't cut the FiT scheme just before the point where PV hit grid parity.

Post edited at 08:27
 Dr.S at work 31 Oct 2020
In reply to Tall Oak:

I think most of this thread has been relating to air:water heat pumps - how do air:air ones stack up?

And in the medium term is hydrogen really likely to be a viable replacement for natural gas in a home heating context?

1
 jimtitt 31 Oct 2020
In reply to Dr.S at work:

> I think most of this thread has been relating to air:water heat pumps - how do air:air ones stack up?

> And in the medium term is hydrogen really likely to be a viable replacement for natural gas in a home heating context?


A friend has air-air with heat recovery, you need a purpose designed house to get the airducts in and get the airflow correct, as a retro- fit it would be virtually impossible.

 wintertree 31 Oct 2020
In reply to Dr.S at work:

> And in the medium term is hydrogen really likely to be a viable replacement for natural gas in a home heating context?

I remain very skeptical about hydrogen.  As a way of storing and shipping renewably produced electricity it’s just not very efficient.  I can see liquid hydrogen having a role as a - relatively - high density fuel source for aviation using engines like the SABRE design for in-atmosphere hypersonic flight but I don’t see it getting wide spread gas grid or road usage.  By the time all the expensive and inefficient and otherwise problematic steps are solved I think we’ll have aluminium ion batteries removing the material scarcity issues from battery tech and 1,000 mile + range EVs.  As for gas central heating, the plan I think should be to insulate properties to the point it’s not needed rather than to decarbonise boilers.

I could be wrong with the future of H2 but I’m staking my digital reputation to my views!

 SAF 31 Oct 2020
In reply to John2:

> I believe some people are not happy with the amount of noise from the pump.

We had an air source heat pump fitted in the summer, it is right outside the downstairs master bedroom window and it really isn't a problem and not much louder than the noise from the oil boiler when it was firing up which was in a similar location but slightly further from the window. The wind over the last week has been far far louder and we have all been sleeping fine.

 summo 31 Oct 2020
In reply to wintertree:

>  As for gas central heating, the plan I think should be to insulate properties to the point it’s not needed rather than to decarbonise boilers.

With the uk's climate the only challenge for 10 months of the year should be managing moisture or humidity, not heating them. 

 Jamie Wakeham 31 Oct 2020
In reply to wintertree:

> As for gas central heating, the plan I think should be to insulate properties to the point it’s not needed rather than to decarbonise boilers.

But insulation is nowhere near as sexy as shiny new technology

Slightly more seriously, there is a limit to retrofitting insulation.  Once you've filled the cavities, replaced the doors and windows, topped up the loft (once you get past about 450mm rockwool there's not much point in going further) then it gets expensive or awkward in most properties.  External wall insulation is horribly expensive, internal is invasive (we have put 50mm celotex on most of the ground floor as part of the redecoration, but I wouldn't want to do it throughout the house).  You get to a point where you think it'd be easier to knock it down and start again... which is why the current building regs are so frustrating, because they're throwing up houses that barely pass.  We should be building new stock that's nigh-on passivhaus.

 wintertree 31 Oct 2020
In reply to Jamie Wakeham:

Agree on all of that.  

The other approach is to embrace living a a cooler house...

 Root1 31 Oct 2020
In reply to Tall Oak:

Question. If you are heating your house with an air source heat pump how do you get hot water for baths etc? Presumably you can heat it to the system temperature and top the heat up with electricity. Is that not expensive?

Answers on a postcard please.

 Jamie Wakeham 31 Oct 2020
In reply to Tall Oak:

Modern AHSP can hit 65 degrees output.  The CoP drops, and in winter it drops quite a bit, but as long as it's still above 1 then it's better than using resistive heating in an immersion.

 jimtitt 31 Oct 2020
In reply to wintertree:

> I could be wrong with the future of H2 but I’m staking my digital reputation to my views!

I'd better write to the German government then and complain they've just wasted 10 billion of my money! For household heating sure H2 is pointless but as an CO2 neutral energy source for heavy goods, rail, shipping and anything heavy that moves there's no proven alternative.

Post edited at 11:14
1
 wintertree 31 Oct 2020
In reply to jimtitt:

> or household heating sure H2 is pointless but as an CO2 neutral energy source for heavy goods, rail, shipping and anything heavy that moves there's no proven alternative.

There's no proven alternative to H2 for low CO2 rail?

  •  Electrified railways?   They've only been around for what, 141 years...
  • The best current combined efficiency of electrolysis and fuel cell generation (as a way of buffering renewable electricity into moving electricity) is 48%; hardly great compared to just sending the power down the wires to the trains.   As long as there's fossil fuel in the mix it's not really "CO2 neutral" as it's much less efficient than direct electric drive and even battery buffered electric drive so the renewables consumed in an H2 system are displacing less CO2 than in an electric drive system.  I don't expect great future gains in the efficiency either. 

Heavy goods - other places are rolling out modern, smart pantograph systems over road freight routes to allow BEVs to do longer distance journeys.  Battery capacities continue to rise and rise, and with aluminium ion technology approaching we could have 1,000 mile range electric HGVs without relatively scarce materials in their batteries before H2 gets going.  In the mean time, better to go with synthetic diesel and not pour money in to a dead end, with battery tech for static and BEV use having far more markets and economies of scale than H2.

Shipping - maybe.  Synthetic diesel presents less challenges, as does adoption of partial wind power.  Really though the global shipping needs to scale back massively.  

General Aviation - H2 or synthetic diesel are the only viable candidates for some time. 

Perhaps I'm wrong but I'm happy to stick my opinion in the sand on this one.  If I am wrong it's win/win because we get another viable renewable technology.  But look at the last two decades and the money poured in to each of H2 and battery technology and look at the returns; I see not great reason to expect that trend to reverse...

 nikoid 31 Oct 2020
In reply to wintertree:

I'm with you on hydrogen. It seems very overblown. My understanding is that at the moment most hydrogen is produced by conversion of fossil fuels, eg steam reforming of methane. OK I suppose if you use renewable energy for the conversion, but there isn't enough renewable capacity for that. Electrolysis of water is an option and whilst it could be done greenly, once we build a few more nuclear stations, it is still energy intensive and therefore won't come cheap. As for hydrogen fuel cell cars where is all the platinum coming from? 

Pie in the sky again innit.

 wintertree 31 Oct 2020
In reply to nikoid:

Agreed; good money for the H2 people in the meantime though.  That $10 Bn jimtit mentioned is for spending over ten years.   Tesla has raised over $20 Bn in capital and is planning to invest $12 Bn from capital and revenue into new battery plants in the next two years.  That's one BEV company and there are other ones much less publicity seeking but with significant capital raised (e.g. Bollinger) and pretty much every vehicle manufacturer is going all-out on BEVs now they're rumbling into action.

One prominent hydrogen lorry outfit is having a bit of a reputational dumpster fire right now - https://arstechnica.com/cars/2020/10/nikola-ceo-downplays-badger-truck-as-g...

Perhaps I was too quick to write off alternatives for general aviation.  After all the Nazi's built a ramjet fighter powered by powdered coal...  https://en.wikipedia.org/wiki/Lippisch_P.13a

 jimtitt 31 Oct 2020
In reply to wintertree:

To electrify the smaller lines isn't economic so Germany has bought hydrogen powered trains to replace their diesels, the battery powered trains have been dumped (as have the long-distance buses). For heavy transport the roll-out of filling stations is nearly complete with 86 operational and the rest under construction, I've yet to see any plans for electrifying the motorway network, only vague investigations which come to nothing.

Shipping is almost certainly going at least partly hydrogen in the near future, DFDS and others are planning either new ships or conversions and ABB are developing megawatt capacity fuel cells for this market.

While we are waiting for wonder batteries and the systems to use them other parts of the world are just getting on with it, look at China's hydrogen plans for example.

Then there's stuff like steelmaking, not mickey-mouse little cars. Thyssen-Krupp are already operating a hybrid hydrogen/mehane smelter for one of their steelworks and building a pure hydrogen one as are Arcelor and Salzgitter, they say it is the only future option.

 rif 31 Oct 2020
In reply to the off-topic side thread:

Some interesting info and thoughts about the possible roles of hydrogen in decarbonisation here: http://www.softmachines.org/wordpress/?m=202008

 nikoid 31 Oct 2020
In reply to jimtitt:

>  look at China's hydrogen plans for example.

I just have, they are making their hydrogen from coal! Because green hydrogen from electrolysis is three times more expensive. Electrolysis costs may come down as their nuclear capacity ramps up but that's a huge gap to close. We'll see I guess.

 Toerag 01 Nov 2020
In reply to Tall Oak:

This would appear to be a game changing tech for Li-ion batteries https://newatlas.com/energy/nawa-vertically-aligned-carbon-nanotube-electro...

 henwardian 03 Nov 2020
In reply to wintertree:

> Focus on my nuanced point then - my fundamental problem isn't the FITs for solar PV, but the way they were funded by adding to all electricity bills.  I can cope with subsiding the rich to get richer if it drives wider adoption of a tech that is in everyone's interests, but those in lower income brackets shouldn't have had to pay for it.  Being funded out of bills and not general taxation made it highly regressive IMO.  Further, that the "we rent your roof" profiteers and their cowboy installers were able to extract profit suggests the system wasn't set up very thoughtfully as the poorest bill payers - including those on punitive pre-pay accounts - were directly funding their profiteering.

That is a persuasive argument. What should the alternative have been though? Means tested electricity cost multiplier to pass the cost on disproportionately to the rich? I think the problem with any taxes that specifically hit the rich and don't really affect everyone else is that they are politically punished because the country as a whole (and especially a lot of the media) are relatively right-wing. So even a Labour gov might baulk at the idea and I think the Tories would dismiss it out of hand.

> Not once the firms are wound down, the ill gotten gains moved off shore and so on...

This is a generic problem with irresponsible companies that affects any number of industries. I don't think it useful to conflate it with whether a particular policy for renewables is good/effective or not.

> They're easy to change however as are normal roof mounted panels.  "Solar roof" panels overlap and are much harder to swap out.  The failures on my test samples are on the water sealing between the PV cells and the "slate effect" ground glass; this allows water ingress and fundamentally changes their appearance, if they were in a real roof it would look awful by now.

Oh, I didn't realise that when you said "solar roof", you actually meant cells built into the primary roof covering, I assumed you just meant panels bolted on. Yeah, I would definitely not go for an integrated design because of concerns about a new product effectively and reliably managing to fulfil roles as both waterproof house exterior AND solar power generation in the medium to long term (for similar reasons, I think solar roads are an absolute gimic that will never(TM) be practical).

 henwardian 03 Nov 2020
In reply to Tall Oak:

The replies from people with experience installing air source and ground source and other alternatives have made interesting reading. It would be great to hear from some more people with first-hand experiences.

 wintertree 03 Nov 2020
In reply to henwardian:

> That is a persuasive argument. What should the alternative have been though?

General taxation.  It may not be popular but it's a lot less regressive than putting it on all bills.  

> This is a generic problem with irresponsible companies that affects any number of industries. I don't think it useful to conflate it with whether a particular policy for renewables is good/effective or not.

I guess we have different philosophies.  I want to agree with you - the FITs and equivalents around the world certainly seemed to move the scale of Solar-PV on to the point that it's now viable stand-alone in a lot of places, so they've been a success in that way.  That doesn't mean I like the scale of resource diversion and enrichment of financial types that it funded in the UK.

> Oh, I didn't realise that when you said "solar roof", you actually meant cells built into the primary roof covering, I assumed you just meant panels bolted on.

Sorry; I could have been clearer.

> Yeah, I would definitely not go for an integrated design because of concerns about a new product effectively and reliably managing to fulfil roles as both waterproof house exterior AND solar power generation in the medium to long term

I did a 200 watt pilot on my bin store.  It's five x 40 W panels each with the appearance of 4 slates, achieved by grinding the glass surface except for smooth "black" lines between the slates.  I'm very glad I didn't it on a "real" roof.  Plastic layers in the weatherproofing have curled off the metal substrate and embrittled, and the silicone sealant literally applied between the substrate and the glass encasing the PV layer in a sandwich are going in places with water ingress which so far wrecks the "slate effect" and is probably not so good for their functional lifetime...

The newer Tesla product looks very nice - slate effect and tougher and harder wearing than slate, and much better engineering.  They also do cheaper ones visually equivalent but without PV which helps keep cost down when doing a whole roof, without the massive hassle of finding a visually matching slate (basically impossible over the range of lighting and wet/dry conditions).  A lot will depend on how well sealed each individual unit is, and how robust the installation is to individual units failing electrically (with respect to how many other units' power generation ability it takes out).  They're not DIY friendly however.  

> (for similar reasons, I think solar roads are an absolute gimic that will never(TM) be practical).

That's a polite way of putting it.  One of the biggest pieces of BS I've seen in the renewables area is my take.

I could see an argument in a few daces time with only ZEVs on the roads to encase motorways in inverted-U section roofs covered in solar-PV with partial light transmission or under-lighting.  In another 25 years the cars won't be getting driven by humans, and the moderating effects of removing wind, rain and snow will improve efficiency of the vehicles, and the control of thermal cycling by not having the asphalt directly absorb sunlight or radiate into the midnight winter sky will preserve lifetimes significantly.   Added bonus - much less noise pollution.


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