SBMS Posted February 12, 2022 Share Posted February 12, 2022 I thought I would resurrect this topic, following the recent increases in the price cap, to canvas opinion.. We're about to start work on our self-build next month, so still within time to decide/change our heating solution. And I must say it's really difficult at present prices to justify the additional benefit of ASHP. I do think it's a bit more of a philosophical decision at times, but wanted to get people's opinions on off-grid LPG vs ASHP. We are estimating a heat demand of circa 16k kWh per annum, and with the predicted cap unit price of electricity estimated to increase to £0.28ppl (https://www.ofgem.gov.uk/check-if-energy-price-cap-affects-you) from April, this is how the numbers are coming out (space heating only, not included DHW) ASHP Total Average heat input 16,839 Electricity ppu £0.28 Efficiency 3.5 Total required kwh 4,811 Total annual electricity cost £1,347.14 Average monthly electricity heating cost £112.26 LPG LPG Price ppl £0.40 KwH Per litre 7.08 Boiler Efficiency 0.9 Required heat input after efficiency loss 18,710 Litres required 2,643 Total annual LPG cost £1,057.08 Average monthly heating cost £88.09 % Saving 21.53% Difficult to justify on a financial basis at present (I've not even included capital costs to install ASHP). Still very much wanting to go this route. I want to 'bet' that electricity will come back down - or that the levy on electricity will be reduced - or that LPG will go up, but a 21% cost delta is quite a difference. Thoughts? 1 Link to comment Share on other sites More sharing options...
CotswoldDoItUpper Posted February 12, 2022 Share Posted February 12, 2022 We are having the same dilemma but we’ve just fixed our LPG at 34+vat p/L for 2 years with Avanti Gas. Kinda made the decision for us! Despite wanting to go ASHP route, we’re sticking with the existing set up and not spending the initial outlay for the ‘green’ alternative. Link to comment Share on other sites More sharing options...
ProDave Posted February 12, 2022 Share Posted February 12, 2022 The figures are close enough that I would choose ASHP just to save having to have a great big bulk LPG tank to accommodate somewhere in the garden. Anything you can do to improve insulation to bring that heat requirement down? Unless it is a big house, that seems high. Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 (edited) 13 minutes ago, ProDave said: The figures are close enough that I would choose ASHP just to save having to have a great big bulk LPG tank to accommodate somewhere in the garden. Anything you can do to improve insulation to bring that heat requirement down? Unless it is a big house, that seems high. it’s a fair point re the tank but most can be sunk underground. Its definitely an over estimate re heat requirement (it’s 260 sq m the house) and we are hoping for lower, but I guess the question was not so much about how to reduce bills with added insulation but how the two energy solutions compare. Might be a relevant question as well for a lot of rural properties with LPG being sold the benefits of ASHP. If electric prices keep rising it gets more difficult to justify. Find it strange that LPG hasn’t risen at same rate as mains gas… Edited February 12, 2022 by SBMS Link to comment Share on other sites More sharing options...
CotswoldDoItUpper Posted February 12, 2022 Share Posted February 12, 2022 9 minutes ago, ProDave said: great big bulk LPG tank to accommodate somewhere in the garden. Get an underground one. Cost to install LPG boiler is significantly less then an ASHP, fuel costs +-10%, no idea about servicing an ASHP but our boiler is £100/yr. I can see benefit for ASHP if combined with decent size solar aray, but that’s even bigger capital expenditure. Personally go for LPG and spend the extra saved on insulation. I’d design the system to be able to just swap the lpg boiler for an ASHP at some point in the future if needed. 2 Link to comment Share on other sites More sharing options...
JamesP Posted February 12, 2022 Share Posted February 12, 2022 From the last year (2021) in our new build, 275sqm, well insulated with PV and MVHR the Ecodan control panel reads out 21000 kWh delivered and 3700 kWh consumed for DHW and heating, I appreciate this is subject to our personal requirements but your heat demand estimate is realistic. Would be interested to know the capital costs for LPG for future reference if you have them. Link to comment Share on other sites More sharing options...
nod Posted February 12, 2022 Share Posted February 12, 2022 45 minutes ago, ProDave said: The figures are close enough that I would choose ASHP just to save having to have a great big bulk LPG tank to accommodate somewhere in the garden. Anything you can do to improve insulation to bring that heat requirement down? Unless it is a big house, that seems high. How much of the electricity to run the ASHP can PV take up Ive just had this conversation with a friend who recommends PV and batteries to run most of the ASHP demands Is this feasible Link to comment Share on other sites More sharing options...
ProDave Posted February 12, 2022 Share Posted February 12, 2022 I have a typical 4kWp / 3.68kW PV system and I can self use most of it without batteries. It offsets roughly 1/3 of our electricity usage. It might not help much with the heating in winter but it certainly helps a lot with DHW heating in the summer. Without the ASHP it would be harder to self use all our PV generation. What about standing charges / maintenance / rental costs of a bulk LPG tank? Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 43 minutes ago, JamesP said: Would be interested to know the capital costs for LPG for future reference if you have them. Nearby supplier provide tank for free. Groundworker a day to dig so few hundred for install. Good LPG boiler around 2500 installed. Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 15 minutes ago, ProDave said: What about standing charges / maintenance / rental costs of a bulk LPG tank? Owned by tank supplier so standing annual charge of £70. Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 45 minutes ago, JamesP said: From the last year (2021) in our new build, 275sqm, well insulated Thanks for this. What insulation did you use and what was your measured air tightness.? Any MVHR? Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 28 minutes ago, SBMS said: Thanks for this. What insulation did you use and what was your measured air tightness.? Any MVHR? Sorry @JamesP - just found your blog and have seen what you built. U-value makeup not dis-similar to our targets although we are brick and block so may not be as air tight. Just on your figures - " 21000 kWh delivered and 3700 kWh consumed for DHW and heating" - is that 21k kWh total for ASHP heating and hot water, with your Solar PV generating everything except 3700 kWh (i.e. your solar array met 17300 kWh??) Link to comment Share on other sites More sharing options...
JohnMo Posted February 12, 2022 Share Posted February 12, 2022 Why not go hybrid and have both ASHP and LPG 1 Link to comment Share on other sites More sharing options...
JamesP Posted February 12, 2022 Share Posted February 12, 2022 2 hours ago, SBMS said: Thanks for this. What insulation did you use and what was your measured air tightness.? Any MVHR? We did not need an airtight test for building control but will commission one to increase the EPC to the mid 90's if and when we sell. Fitted MVHR which runs in the background 24/7. The figures above are for both heating and hot water. Those figures indicate a CoP of over 5 though I cannot guarantee the accuracy of the unit. Our PV generates about 3300kWh per year which we probably consume at least a third as we have a PV diverter fitted to the immersion. Link to comment Share on other sites More sharing options...
CotswoldDoItUpper Posted February 12, 2022 Share Posted February 12, 2022 2 hours ago, ProDave said: What about standing charges / maintenance / rental costs of a bulk LPG tank? £66+vat annual standing charge. Owned by supplier. Link to comment Share on other sites More sharing options...
crispy_wafer Posted February 12, 2022 Share Posted February 12, 2022 Timely thread, thanks for starting @SBMS , I'm waiting to see what they come out with with regard future incentives for Heat pumps, however I'm in a similar boat with a choice to make, I'm bricking it over electrickery prices, and whilst I'm doing my best to insulate, and make airtight, I ultimately don't know how good a job I've done or not until I'm living in it. Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 Hi @crispy_wafer at present the main incentive seems to be the Boiler Upgrade Scheme which offers a 5k grant for ASHP installation. It kicks off in March and is replacing the renewable heat incentive scheme. 1 Link to comment Share on other sites More sharing options...
Bonner Posted February 12, 2022 Share Posted February 12, 2022 1 hour ago, SBMS said: at present the main incentive seems to be the Boiler Upgrade Scheme Have the rules been confirmed yet? Last time I looked legislation was still in draft (which does cover self build new installations) Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 I believe the consultation closed last year and the government response confirming the scheme published here in October: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1026446/clean-heat-grant-government-response.pdf Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 3 hours ago, JohnMo said: Why not go hybrid and have both ASHP and LPG Hybrid systems aren’t eligible for the Boiler Upgrade Scheme. Link to comment Share on other sites More sharing options...
JohnMo Posted February 12, 2022 Share Posted February 12, 2022 Calor web site says they are? Link to comment Share on other sites More sharing options...
SBMS Posted February 12, 2022 Author Share Posted February 12, 2022 25 minutes ago, JohnMo said: Calor web site says they are? If you have a look at page 33 of the previous document the government response states: “We maintain that hybrid systems – a system comprising of a heat pump and fossil fuel boiler – will not be eligible for the Boiler Upgrade Scheme.” Link to comment Share on other sites More sharing options...
SteamyTea Posted February 12, 2022 Share Posted February 12, 2022 39 minutes ago, SBMS said: Hybrid systems aren’t eligible for the Boiler Upgrade Scheme. 34 minutes ago, JohnMo said: Calor web site says they are? They may be eligible until the scheme changes in March. Link to comment Share on other sites More sharing options...
joe90 Posted February 12, 2022 Share Posted February 12, 2022 (edited) 3 hours ago, SBMS said: Boiler Upgrade Scheme which offers a 5k grant for ASHP installation. Personally I think any grant should be for insulation so whatever fuel you use to heat it will use less ?♂️ As an aside, my builder, who had a stroke just after finishing my build, has just been told he can upgrade his old storage radiators, have cavity insulation and additional loft insulation for free, grant based on his benefits as a stroke patient ? Edited February 12, 2022 by joe90 2 Link to comment Share on other sites More sharing options...
SteamyTea Posted February 12, 2022 Share Posted February 12, 2022 2 minutes ago, joe90 said: Personally I think any grant should be for insulation so whatever fuel you use to heat it will use less Personally I think we should scrap grants, subsidies and incentives and just use fuel price as the 'nudger'. People are very happy to comment on how much their houses have risen in value, then whinge and whine about the cost of fuel. (expletive deleted) em, let them borrow a bit of cash against the property. Link to comment Share on other sites More sharing options...
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