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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
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  1.  
    DJH said >>>>> ”The whole system is designed to encourage investment into low cost production, by giving such investment larger rewards. Then it's complicated further”

    Agreed, and another complication is that when the rewards got too much, the gov applied windfall taxes on top of CT and VAT so most of the extra revenues are being diverted to the Treasury, instead of going to the consumer as lower bills.

    Ironically the windfall rewards are mainly made by the old ROC /FiT projects which were invested and paid for many years ago. The more recent expansion of renewables has been done under CfD where the investors make exactly £0 extra rewards from the higher prices - the windfalls go to the govt, in exchange for insurance against lower prices in future.
    •  
      CommentAuthordjh
    • CommentTimeJun 7th 2023
     
    Posted By: WillInAberdeenanother complication is that when the rewards got too much, the gov applied windfall taxes on top of CT and VAT so most of the extra revenues are being diverted to the Treasury, instead of going to the consumer as lower bills.
    But the consumers buy from retailers, whilst the windfalls went to generators. Retailers and generators are not the same in general.

    To illustrate. I buy my electricity from Octopus and their prices have been tracking the various government limits. I also own part of a wind turbine through Ripple and the money I am paid has gone up because they are getting paid more. The money from Ripple is paid into my Octopus account, and I've just reduced my monthly payments quite significantly as a result. In this case the government did listen and the windfall did not go to the treasury.
  2.  
    I'm not a customer but AIUI Ripple are too small for CfD or to fall under the windfall tax, which was introduced in January for the more significant size generators, unless you have better inside info?

    (Edit: they don't bother chasing the very smallest companies < ~10 MW for windfall tax, or FiT generators such as domestic solar panels.)

    In general yes, generators are different from retailers, although most of the big six companies like Octopus are both. Jeff's question was why generators don't pass their windfall on to retailers (in the form of lower competitive market prices) and hence on to customers. Answer is that the renewable generators mostly paid out their windfalls as tax, and a few minnows paid them to shareholders, as happened in your case.
    •  
      CommentAuthordjh
    • CommentTimeJun 7th 2023
     
    Ripple was originally within the government's tax clawback, but persuaded them (presumably along with other companies and with lobbying by people like me) to move them outside it.

    Generators can't pass their windfall to retailers. They sell in a spot market to the network and the price is not set by them. They are all paid at the marginal rate, usually gas. So they don't even know who is using/buying it, even if that concept makes sense.

    See e.g. https://www.instituteforgovernment.org.uk/article/explainer/electricity-market for a better explanation.
  3.  
    Yes indeed, but as Tom mentioned, the government announced that they were going to change that. (Specifically change the pricing arrangements to 'pay as bid' instead of 'pay as cleared'). Then, they announced that renewable generators would go onto CfDs instead (fixed price, completely independent of the market price). Then it all went very quiet, and then the new lot announced they were imposing windfall tax instead, and the opposition agreed with that.

    So it's just a political choice that renewable generators are not selling electricity at lower prices than gas generators do, presumably in response to lthe lobbying you mentioned.

    Here's what Kwarteng said a year ago - now all buried in 'further consultations'. https://www.gov.uk/government/news/uk-launches-biggest-electricity-market-reform-in-a-generation
    "de-coupling costly global fossil fuel prices from electricity produced by cheaper renewables"
    •  
      CommentAuthorfostertom
    • CommentTimeJun 7th 2023 edited
     
    Nice one Dave - thanks.

    Pity about Kwarteng - often talked sense. Was he swallowed whole?
    •  
      CommentAuthordjh
    • CommentTimeJun 7th 2023
     
    "it's just a political choice"

    Changing the way the electricity market works will take years. First they have to agree a plan, then argue about the plan and finally reach a conclusion, then write legislation and regulations and pass them into law, and then build new trading systems and then wait until all existing forwards contracts have completed ... and that's all assuming nobody takes anybody to court in the meantime. :devil:

    So there's no way it would help in the current situation.
    •  
      CommentAuthorfostertom
    • CommentTimeJun 8th 2023
     
    Posted By: djhFirst they have to agree a plan, then argue about the plan and finally reach a conclusion, then write legislation and regulations and pass them into law
    etc etc - just like nationalisation!
    • CommentAuthorMike1
    • CommentTimeJul 19th 2023 edited
     
    • CommentAuthorrevor
    • CommentTimeJul 19th 2023
     
    Posted By: Mike1Just spotted this article about the growth of heat pumps in France - 621,000 installed last year, compared to 55,000 in the UK.

    https://www.mcscharitablefoundation.org/news/2023/7/17/new-report-france-cuts-heating-emissions-ten-times-faster-than-uk-with-heat-pump-roll-out

    Full report here: https://www.mcscharitablefoundation.org/s/MCSCF-Heat-Pump-Report-2023-md38.pdf


    What is it that the French are doing that the UK is not?
    • CommentAuthorMike1
    • CommentTimeJul 19th 2023 edited
     
    Posted By: revorWhat is it that the French are doing that the UK is not?
    That's mainly what the report's about :)

    The short version is that France is taking it seriously, the UK isn't.
    •  
      CommentAuthordjh
    • CommentTimeJul 19th 2023
     
    France has a lot more places that 'suffer' from hot weather than the UK does, so before I look at the report I'll hazard a guess that a lot of the French installs are reversible air-air models (otherwise known as reversible air-conditioning units) :devil:
    • CommentAuthorMike1
    • CommentTimeJul 19th 2023
     
    Another interesting chart from the EHPA. The UK is bottom again.
      Heat pump sales per 1000 households by country.jpg
    • CommentAuthortony
    • CommentTimeJul 20th 2023
     
    Heat pumps also work as air conditioners (air cooling)
    • CommentAuthorowlman
    • CommentTimeJul 20th 2023 edited
     
    Posted By: tonyHeat pumps also work as air conditioners (air cooling)




    Are you referring to Reverse Cycle Air to Air Heat pumps, or Air to Water? I assume the former.
    •  
      CommentAuthordjh
    • CommentTimeJul 20th 2023
     
    Posted By: tonyHeat pumps also work as air conditioners (air cooling)
    Heat pumps* can be made to be reversible, so that can be true. But they can also be made to not be reversible, so it isn't true. Guess which UK politicians decided to subsidise?

    * A heat pump can either be designed to produce cool or to produce heat (of course they actually always produce both so it's not a capability decision but an engineering one of how the pieces are put together and whether or not a reversing valve is fitted. And of course which of the heat exchangers use what other medium to source or sink the heat.
  4.  
    All air-water heat pumps work in reverse, during their defrost cycle.

    So all the hardware components are fitted, it's just a software setting that prevents them running long term as air conditioners.

    The major reason for this is to prevent radiators/ufh from running cold and dripping with condensation. The other major reason is eligibility for the subsidy DJH mentioned.
    • CommentAuthorrevor
    • CommentTimeJul 20th 2023
     
    Posted By: WillInAberdeenThe other major reason is eligibility for the subsidy DJH mentioned.


    A bit like when Ed Davey was Minister for energy in the coalition government. He decreed that you could not have RHI for solar thermal and be able to use the same water for heating your house. Its all about giving you something but maintaining control by holding something back. Suffice to say I ignored the MCS and RHI and installed a thermal store and enjoy the bit of winter sunshine that pre heats my water that goes round my UFH. We are led by those educated (usually very well) in politics, economics, the classics philosophy etc. We need politician that know one end of a screwdriver to the other.
    •  
      CommentAuthordjh
    • CommentTimeJul 20th 2023
     
    Posted By: WillInAberdeenAll air-water heat pumps work in reverse, during their defrost cycle.
    That may be true, but not all air-conditioners are reversible, and they are heat pumps.
  5.  
    That may very well be true, and neither are fridge-freezers or bike pumps or diesel engines* reversible. Don't think anyone said otherwise!

    Next installment of Heat Pump Gate: the Guardian are reporting that gas companies and gas boiler manufacturers have hired a PR company to discredit heat pumps and delay their introduction, including by planting articles in certain other newspapers to criticise heat pumps and spread disinformation. Don't believe everything you read about heatpumps in the newspapers folks, it might very well not be true!

    https://www.theguardian.com/environment/2023/jul/20/gas-boiler-lobby-uk-heat-pump-plans-leak

    It would really be a shame if home heating becomes a polarised culture-war issue, with rival newspapers using it as a stick to hit "the other side" with, we haven't really got time for that kind of nonsense.


    *The compression stroke in a diesel engine heats the air to 500⁰-700⁰C so the fuel is ignited without a spark. Meanwhile, people complain about home heat pumps at 70⁰ being "too high temperature"! :-)
    • CommentAuthorowlman
    • CommentTimeJul 20th 2023
     
    Even if you could reverse cycle a mono-block HP to run continuously, chilling the fabric of the building in order to obtain some, possibly very small, air con effect sounds like a bad idea to me.
    Notwithstanding the RHI and the pipework/radiator condensation effect that Will mentions, there's the fact that cold air sinks, how do you square that with an underfloor grid designed to heat.
    Even if everything else worked, there is the issue of pump sizing. A pump designed to produce relatively low temp continuous heating I doubt would have the "guts" to produce fast cooling that was noticeable.... Oh, and the next day you need a bit of heating, 'cos the weather's changed in our variable maritime climate; so your cold walls and floors present extra work for your heat pump. That all sounds really eco friendly and efficient. :wink:

    Making a single mono-block system that was primarily designed to heat water do the opposite, smacks of sows ears and silk purses.
    Maybe the much maligned politicians weren't so daft or badly advised after all.

    Just go Air-Air; forget subsidies, and enjoy cheaper year round comfort and versatility, it works a treat.
    •  
      CommentAuthordjh
    • CommentTimeJul 20th 2023
     
    Posted By: WillInAberdeenfridge-freezers
    I think you'll find that some use a reversing valve for the defrost cycle. The other items aren't heat pumps, so aren't what we're discussing.
  6.  
    They mechanically move heat from cooler to hotter by doing work, so yes they are all heat pumps ;-)
    https://en.m.wikipedia.org/wiki/Heat_pump_and_refrigeration_cycle



    Edit to add: agree about the air-air, but many of the current models of monobloc air-water heat pumps are available as heating-and-cooling or as heating-only configurations. Eg Daikin Atherma 3 does 11kW heating at CoP=4.8, and 12kW cooling at EER= 5.3. Guess you'd only choose the cooling-enabled variant if you were not in UK subsidy regime and were using fan coil emitters, or were very careful about cooling the floor temperature very slightly.
    •  
      CommentAuthordjh
    • CommentTimeJul 20th 2023
     
    Posted By: WillInAberdeenThey mechanically move heat from cooler to hotter by doing work, so yes they are all heat pumps ;-)
    They compress gases, yes. A diesel does it by burning fuel. The article you link to makes the heat pump concept explicit "Heat pump and refrigeration CYCLE". If you look at the Wikipedia article about Heat Pumps themselves, you'll see they say "A heat pump is a device that uses work to transfer heat from a cool space to a warm space by transferring thermal energy using a refrigeration cycle". Neither of the devices use a refrigerant cycle, and the purpose of neither is to transfer heat from a cool place to a hot place. Indeed removing (wasting) the heat from a diesel engine is a design problem for such devices.
  7.  
    Getting tedious, but in my previous post I was explicit that the compression stroke of a diesel engine heats the refrigerant fluid (cold air in this case) to make it hot enough to ignite the fuel, which will subsequently be injected in the next stroke of the 4-stroke CYCLE. The temperature rise during the compression stroke comes from mechanical work done by the flywheel driving the piston - no fuel is burned during the compression stroke.

    In the same way, a bike pump has a 2-stroke CYCLE of suction and compression. The working fluid (air again) and pump get heated, as is familiar to anyone who pumps up skinny tyres, they know they're doing mechanical work.

    Persevering with the smileys ;-)
    •  
      CommentAuthordjh
    • CommentTimeJul 21st 2023
     
    The heat transferred in a heat pump mainly doesn't come from the work done. If it did then the COP would be <= 1. The whole point of a heat pump is that the COP is larger than 1 because it moves heat, not because work creates it. The refrigerant cycle with its attendant phase changes is a vital part of a heat pump. It is fundamental. Again, a diesel engine and a bicycle pump are not heat pumps.
    • CommentAuthorwookey
    • CommentTimeAug 4th 2023
     
    For those that can't be bothered reading that heat pump report. Mr EHPA (Jan Novak) was on Watt Matters talking about adoption rates and reasons and the fact that it's got 'controversial' in the UK and Germany whilst France and Scandiewegia are just getting on with it.

    May 5th Episode: https://foresightdk.com/wm-ep33/

    It's a very good podcast and it's nice to have something with a European focus when so much other good stuff is US-focussed. (Volts, The Interchange, Energy Gang, The Energy Transition Podcast, War on Cars).
    https://foresightdk.com/watt-matters-podcast/
    • CommentAuthorMike1
    • CommentTimeAug 16th 2023
     
    Posted By: wookeyMr EHPA (Jan Novak) was on Watt Matters talking about adoption rates and reasons and the fact that it's got 'controversial' in the UK and Germany whilst France and Scandiewegia are just getting on with it.

    May 5th Episode: https://foresightdk.com/wm-ep33/


    I finally caught up with this today - very good - thanks for the tip-off!
  8.  
    I do find it depressing the negativity towards heat pumps on here. They clearly work, and work well if used properly and should be no issue at all in the sort of houses people on here are building (or creating from older properties).

    My biggest regret on my build (which started just over 10 years ago, and specced over a couple of years preceding that) was installing a gas boiler (partly on the basis of the misinformation that's still going on now and partly falling for the 'switch to hydrogen' which it's now clear is just not going to be realistic or practical). I don't think anyone should be installing a gas boiler on a new build now.

    Re France I was going to say 'no real issue with air-air heat pump as air con so long as you're powering it from locally installed solar'.... but surprisingly few solar installs in France given their weather
    According to wikipedia
    France national total install 17Gw. H/h installs 460k = 1.6%
    UK 14.4Gw H/h installs 1.2m which I make over 4%
    • CommentAuthorMike1
    • CommentTimeAug 17th 2023
     
    Posted By: Simon Stillsurprisingly few solar installs in France given their weather
    According to wikipedia
    France national total install 17Gw. H/h installs 460k = 1.6%
    UK 14.4Gw H/h installs 1.2m which I make over 4%

    Not something that I've looked at until now.

    According to Solar Energy UK
    - 556MW of capacity was installed in the _first_ 6 months of 2022 (up 80%)
    - The total installed capacity in the UK is 14.6 GW (presumably at the end of 2022)

    While France Territoire Solaire reports that
    - 1,315 MW of capacity was connected in the _last_ 6 months of 2022 (572 in Q3 + 743 in Q4)

    And the French Government reports that at the end of Q1, 2023
    - The total installed capacity in France was 17.2 GW (after another 601 MW had been connected that quarter)

    So it seems that France was behind, but that is is now installing at at least double the UK rate.

    I'd guess that may be partly due to the 2021 Climate and Resilience Law, which requires PV panels (or a green roof) to be installed on all new or renovated commercial buildings >500m², over all car parks >500m², and over all office buildings >1,000m². I'm not sure when those obligations kicked in, but it's certainly mentioned that many of the new PV connections are for large schemes.

    Comparing the % of electricity generated by PV in the two countries is probably misleading, as the UK uses less electricity but more gas.

    https://solarenergyuk.org/resource/impact-report-2022/
    https://franceterritoiresolaire.fr/45eme-edition-4e-trimestre-2022/
    https://www.statistiques.developpement-durable.gouv.fr/tableau-de-bord-solaire-photovoltaique-premier-trimestre-2023-0
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