Green Power

Solar and wind don't even really use the land. You can still grow crops and graze animals under wind turbines and solar panels. Perhaps wind turbines better for crops so they don't block out the sun, and maybe solar better for grazing animals so they get the option to choose between shade/shelter and sun.

Thanks - check the rest of the blog if you're interested - it is more of a climate blog though, so depends on your interest in that rather than heat pumps specifically.

In 2022 I installed a heat pump in a property I was renting out and in 2023 moved in there myself and have now lived though a whole winter with the heat pump as well. I explain on my blog why I did it, how much it cost, and what issues there were, and so on. It's 1,000 words long, and at the below link. I previously did two threads about the cost and environmental impact of the install on this forum which are linked to in the post below. I hope this helps and let me know if anyone has any questions. https://foxesinchile.wordpress.com/2024/04/09/my-heat-pump-experience/

Not yet but once Donald Trump has become President in 2025 you can but only for children of journalists, illegal immigrants or democrats.

To elaborate: "You are punching a young child in the face for no reason. Please stop." "Ah yes, but I did not have children. Had I done so, my children would inevitably have got into fights and punched children in the face a few times at least. By avoiding having children, I have stopped at least ten fights from happening. So surely that is more important than just this one fight. You had three children, so you caused many fights to occur. Much more than me." "But you can get a punchbag or join a boxing club. It requires a change in how you do things but it's really just as good or better. Here, check out this leaflet about our local free boxing club." "Shut up! You are making me mad by proposing a change in how I do things. I do not like change and people telling me what to do. Population is the real problem. There are too many of us. Can you honestly dispute the inevitable fact that with half the population gone people being punched in the face would occur half as often? There is no way you can ever achieve the same gains by stopping one little fight at a time. This fight is negligible in the context of all the violence in the world. My contribution to that total is miniscule."

Having a child means you give someone an entire life. The corresponding carbon emissions might cause one year's worth of life loss or suffering. It is a net win by far. Whereas getting another gas boiler will cause some emissions but with no real positive side or net benefit since it will overall work out (in the long run) about the same hassle and probably same lifetime cost or more than a heat pump (in some/most cases) A couple halve their emissions by going vegan and not flying which causes the same effect as them having one less child. That is far less of a sacrifice (arguably little to no sacrifice) than a person not getting to be born and live their life. Also, if you are responsible for your kids' emissions, does that mean your parents are responsible for yours? That doesn’t seem to make sense. We can’t be responsible for everything our children do. In fact, apart from climate change, no-one suggests we assign blame or credit for our children’s activities in other areas. Why do we do this purely on climate change? It's weird that this population argument ONLY crops up in the context of climate change. No one ever says "the best way to reduce plastic is to have one less child" or "the best way to fix the crisis of affordable housing is to have one less child". This argument NEVER comes up in ANY other area where it would equally apply. There is no good reason for this and it is simply an illustration of the climate denialism permeating society that such a silly argument is allowed to stand. Whether you have a child or not is up to you, as is whether you get another gas boiler. But connecting the two is almost always just a way to avoid talking about reducing your own emissions, it's more whatsaboutism and denialism.

Well using gas directly is using 100% gas and using the electricity grid means using only 40% gas. And that will decline over the lifetime of the heat pump so you can call it maybe 25% gas. So that's 4x better. However, heat pumps use electricity 4x more efficiently (350% efficient) that burning gas directly (80-90% efficient). So 4x and 4x again and we're at 16x better. But we still need to factor in efficiency losses to generate the electricity so it's not really 16x better. But clearly a lot better.

The issue with biogas is that there isn't every going to be enough of it to take a large % of the total gas demand. To do so would require a lot of land use. But doing it as an individual in the right way can work I think.

My kWh for gas includes hot water, but most of it is heating. That may slightly affect your calculation above, but not much. What could be helpful to people following this topic is if you explain what year your house was built in, how well insulated was it from the start. If most of the heat demand reduction was done well after the original build, that might be an interesting case. I think I did say earlier that insulation can only save 5%-30%, depending on the type of insulation (or something along those lines). That wasn´t a very clear statement (sorry) but I meant that each type of insulation can save this amount. Say it´s 30% for cavity wall insulation in every wall. 10% or 20% for loft insulation. 5% for sealing paces with drafts. These are rough guesses. I just read these numbers in some articles. In theory sure you can get a big overall saving if you spend thousands and thousands on a massive retrofit. I´m not sure how many of the people that just respond to "heat pump" with "insulation" are actually doing that though. It only cost me about £1000 extra to put in a heat pump (when you factor in that the gas boiler was dying and I would in any case have had to get a new one). It would have cost way more to do a deep retrofit, I think. I do think that the kind of deep retrofit needed to achieve 60%-90% reductions in heating demand on old houses is likely going to be impractical, expensive, or difficult, but I could be wrong, I don´t have a great knowledge on this, and I don´t feel that strongly about it, and it will vary by case. For my house, the side wall already has cavity wall insulation and has had for years. The other two walls are difficult/expensive impossible to do (I´ve been told) because of the type of wall with cladding on it. I did increase the loft insulation a few months prior to installing the heat pump. I have also had someone look at the window seals and a few are not working properly, so I plan to replace those next summer. I´m not sure what else I can really do. There is also the fact that replacing a gas boiler with a heat pump reduces the emissions impact of hot water, whereas insulation changes don´t have (much) effect on that. Maybe we are arguing too much about heat pump or insulation, though. If anyone has achieved a deep retrofit with similar levels of emissions reduction or better than what I did with a heat pump, then good for you.

The 77% is calculated in the original post in this thread. Keep in mind that the heat pump was only installed a few weeks ago and so this is based on an untested rough prediction of a COP of 3.4.

This is a case study based on what actually happened in the specific case of my house. The company specifying the heat pump decided to add extra radiators so extra radiators were installed and paid for. I am aware that in some other installations no radiators are added, and that heat pumps can work without additional radiators in many cases.

By my calculations the estimated reduction from putting a heat pump in is 77%. And other estimates from others found online have come out similar. There is no way you can reduce your emissions by 77% with insulation. To do that, you would need to be able to reduce your bills by 77% after putting in the insulation, and no one manages that. You can search online for the amount of savings from insulation and it is more in the range of 5% - 30% depending on the type of insulation. There is one area where it might be true and that is new build houses where it is possible to achieve greater reductions with insulation. For the cost of a gas boiler, I think you are referencing my other thread which I linked to above. As I said in that thread, For the price of the boiler, I considered the size of my house and used (I did not get any quotes) How much does a new boiler cost? - Which? (partly paywalled), Guide to New Boiler Installation Costs 2021 and Boiler Calculator - Cost of New Gas Boiler with Installation From the average of these articles I estimate £2,600. However I only paid £1400 for boiler in 2011 (same house), which would be £2000 today with inflation. So I decided to split the difference and call it £2,300. The prices on Screwfix are I assume boilers without installation included which explains why they average nearer to £1000 rather than £2000. My prices (for both boiler and heat pump) include the cost of the installation. For my specific case, the boiler was dying so had I not installed a heat pump I would have had to replace the boiler. So for my case it is relevant to include the emissions of a new boiler in the relative calculation. But if you were considering replacing say a 5-year old gas boiler with a heat pump, then the relative calculations of cost and environmental footprint could of course in such a case exclude the gas boiler`s manufacturer and cost.

For my specific case, had I installed a boiler no radiators would have been required. Whereas by installing a heat pump a few extra radiators were required, hence further footprint. Had I installed another boiler it likely would have been another combi with no hot water storage tank. I´ve ignored end of life recycling because I´m confident that it is a low % of the total - perhaps 1% or 3% - and therefore won´t affect the total result. The reason I know it´s low is partly because I´ve seen studies and expert opinion over the years that always say this, and partly it´s just common sense. Just think about what goes into taking something to the dump vs all the complex parts of a supply chain to manufacture something.

Heat pump running costs were discussed on another thread I did, so if anyone is interested we can discuss there. You are already aware of this other thread of course, but just replying for the benefit of others.

This will be a comparison of the forecast climate impact of installing heat pump vs gas boiler and then 13 years of use, for the specific case of my house. I'll ignore end of life (disposal) emissions for simplicity: they tend to be small. I estimate the heat pump at 10.4 tonnes CO2e, the gas boiler at 44.9 tonnes, for a savings of 34.5 tonnes over 13 years. Heat Pump Operation 2727kWh per year (see my other post "Heat Pump vs Gas Boiler: Lifecycle Cost Comparison" to see how I got this figure) x 0.13kg CO2e/kWh grid carbon intensity = 0.35 tonnes (the assumption on the carbon intensity is UK grid is about 0.20kg/kWH for now, declining steadily to a forecast 0.06kg in 2035, for an average of 0.13 during the period.) Add on very rough guesstimate 30% to account for emissions in the production and maintenance of the electricity grid and power plants and production of generation equipment = 0.46 tonnes 0.46 tonnes per year for 13 years for a total of 5.99 tonnes over 13 years Refrigerant The Dakin model I have uses R32 which has a global warming potential of 675, which means it causes 675 times more warming than the equivalent weight of CO2. To get a CO2 equivalent (CO2e) warming, you can therefore take the 2.2kg of refrigerant and multiply by 675 which gives us 1.49 tonnes of CO2e. I'm guestimating that the refrigerant will leak out completely once during the 13 years, or not be properly disposed of at end of life. (2.2 figure is actually from a Mitshibishi Ecodan, as I couldn't find the figure for my Daikin.) Manufacture To work out the climate impact of the production of the heat pump, I estimate 0.35 kg CO2 / £ as a typical carbon intensity of manufactured goods (Mike Berners Lee arrives at this estimate, and I've found it often fits when cross checked against more rigorous studies). So I then apply 0.35 x £8405 which is the full carbon cost of the heat pump installation = 2.94 tonnes. TOTAL = 10.42 tonnes CO2e. (5.99+1.49+2.94) = 0.80 tonnes CO2 per year. Gas Boiler Operation 11588kWh annually (from meter readings) is 2.12 tonnes CO2e per year according to carbonfootprint.com - Home of Carbon Footprinting (it has a converter where you type in the kWh of natural gas and it gives you the CO2). I´ve added 60% extra (x 1.6) made up of 35% additional for methane leakages (sources and calculation on request) and 25% (a very rough guess) for the other emissions in the supply chain like transport and storage and tankers and building pipelines and operating businesses. So 2.12 x 1.6 = 3.39 tonnes CO2 per year (2.12 x 1.6) or 44.1 tonnes CO2e over 13 years. Manufacture I use 0.35 kg CO2e per £ again x £2300 estimate for a gas boiler and we get 0.8 tonnes CO2e. The reason it's a lot lower than a heat pump is because the heat pump has the hot water tank, the radiators, and a more complex installation which means more labour time which means more economic activity behind that in office and other company emissions. TOTAL = 44.9 tonnes CO2e (44.1+0.8) = 3.45 tonnes CO2 per year. Relative Difference The heat pump is 77% lower overall. It's an estimated carbon saving of 2.65 tonnes per year.or 34.5 tonnes in total. Comparison to Other Life Choices The annual emissions of this heat pump are about the same as the dietary emissions of a vegan growing their own vegetables and composting, whereas the gas boiler is about the same as someone who eats an above average amount of meat with a high food wastage. A heat pump's annual emissions are similar to an electric car, whereas a gas boiler is similar to a petrol car. I think a heat pump may be the biggest reduction you can achieve in the UK with a single decision. The reductions are about the same as each of driving an electric car or going vegan or deciding not to fly, but that's only true if you stick to such commitments for a very long time. You may decide to go back to a petrol car, or meat, or flying. In reality, vegetarian meals, not flying etc are a sequence of many decisions. Whereas buying a heat pump locks in savings virtually guaranteed since you are very unlikely to decide to rip it out and go back to a fossil fuel boiler. Those savings are also locked in for your whole family, not just you. And these numbers are for a 2-bed end terrace at 71 square metres. If you have a large detached house, opportunity for carbon savings will be bigger.

Say Radian is right that under 20W - call it an even 20 - for a pump. We still have 35W for a fan, so we now have 55W total. 55W x 4 hours = 220Wh = 0.22kWh x 365 days = 80.3 kWH/year. x £0.34 /kWH = £27.30/year = £355 over the 13 years.

When I say 4 hours per day I mean average throughout the year. Say zero hours in summer, 3 in autumn/spring, and 10 in winter. Average 4. So you have 35W for the fan, the article I posted also lists 65W for a pump, for a total of 100W. Ignition we can probably ignore as negligible. I'm assuming that with a heat pump the circulation pumps' electricity consumption has already been factored in when people quote heat pump COPs or the total electricity they consume, so doesn't need to be considered separately (but this is a guess).

Just got some feedback from the tenant that neither they nor the next door neighbour (who is pretty close with it being a terraced house and the heat pump sited near to them) can even hear it. So that's good that the noise is low.

"The minimum electrical consumption of a gas boiler is 65 watts. This is in the phase of operation of the circular pump, and at the time of electric ignition - 120 W, i.e. almost twice as high. If the fan is on, then it consumes electricity - another 30-35 watts" "Having studied the technical documentation for the products of Bosch, Baxi, Vaillant, Ariston and others, we see that the electric power of floor units is in the range from 100 to 200 W, and floor - from 15 to 160 watts" Source: https://en.exactosystem.com/1584-gas-boiler-power-consumption-how-much-electricity-is.html or https://engineer.decorexpro.com/en/otoplenie/kotly/elektropotreblenie-gazovogo-kotla.html (it looks like one of these is a copy and paste from the other) If the average throughout the year is 4 hours per day of boiler use (this is a guess, let me know if anyone can improve this), and assuming that the use is zero or negligible when turned off (again, a guess) then that's 100W x 4 hours = 400Wh = 0.4kWh x 365 days = 146 kWH/year. x 34p /kWH = £50/year = £650 over the 13 years. I may update my cost calculation in a new thread next year when I have a real electric meter reading and I can take into account some of your other comments and move some of the data towards the average opinion on here in cases where no better source was found.

It doesn´t have to be 4 though, it only has to be about 3.4 when you allow for gas boiler efficiency. Maybe 3.2 if we accept some reduced repair costs with heat pump. Also, where do you get 44p per kWH? My source is https://www.moneysavingexpert.com/utilities/what-are-the-price-cap-unit-rates-/#tool which has electricity at 34p not 44p. At 34p, that´s a difference of about 3.4, or 2.9 after allowing for gas boiler efficiency. If we accept some reduced repair costs with a heat pump, even a 2.7 COP might be cost parity.

Steamy Tea, thanks for the carbon intensity graph. However, it shows carbon intensity now or tomorrow. What would be more useful would be the average for 2021, and the average for 2022 so far. Hugh F, Your 86 Baxi lasted longer than my 2011/2012 Baxi. Thanks for all the comments on boiler longevity. I may have been pessimistic on my gas boiler longevity by the look of all your feedback. But note that however long gas boilers last will have a minimal effect on the relative cost vs heat pump, since the running costs are the majority of the costs.

Some portion of my cost will be the company's operating costs, such as vehicles, electricity bill, IT network, paying taxes, the salary of the receptionist and so on. And some will be profit. Some will go to cover the costs of people that get quotes and don't go ahead.

I´m not sure even that is true. If the grid is a mix of gas and renewables, surely it is a cleaner than gas. (There is hardly any coal.) Couldn´t quite find the answer in your source, although I only had a couple of minutes to spare to check. But, this is a question about whether heat pumps are 70% better on climate change or 85% better, but it´s clear that they are better. I have done a calculation for my specific case which I can share another day in a separate article.

Thank you all for your feedback. I think people have a “stick with what you know” attitude or resistance to chance and this has subtly affected the arguments too much in favour of gas boilers. I suspect I´ve seen this attitude on this forum at times, but also in broader society. Prices have shifted in favour of electric recently. Some of your advice that heat pumps are more expensive to run is probably out of date. Modern gas boilers are certainly claimed at 90% rather than 80%, but I´ve seen several posts on other forums from people saying that they did very careful calculations and reality is nearer 80%. I don´t have a high confidence in this. Further information/sources/studies would be helpful. Thanks for the feedback on gas boiler lifetime. Mine was falling apart and in desperate need of replacement after 10-11 years. What have others experiences been? I would define “lifetime” as the length of time before it gets replaced. It´s possible that gas boiler installed in 2022 will be proactively replaced for climate change reasons by about 2035 even if they are working fine.

Sources and notes for original post. * Your house size can be found on your energy performance certificate, which can be searched for online if you don’t have it. **If you google “gas boiler lifetime” 10-15 years is a common figure in various articles and fits with my experience. If you google “heat pump lifetime” and look at everything that comes up it varies 10-30 years, I think 17 looks about the average of the opinions. *** For the price of the boiler, I considered the size of my house and used (I did not get any quotes) How much does a new boiler cost? - Which? (partly paywalled), Guide to New Boiler Installation Costs 2021 and Boiler Calculator - Cost of New Gas Boiler with Installation From the average of these articles I estimate £2,600. However I only paid £1400 for boiler in 2011 (same house), which would be £2000 today with inflation. So call it £2,300. **** 11588kWh per year is based on actual meter readings for the house from October 2021 and October 2022. # https://www.moneysavingexpert.com/utilities/what-are-the-price-cap-unit-rates-/#tool These are national prices. Prices vary slightly by region: https://www.moneysavingexpert.com/utilities/what-are-the-price-cap-unit-rates-/#regional This is for direct debit – for others (prepayment, or paying on receipt of bill) that can be found via first money saving expert link above. Note that the standing charge for gas is eliminated when you install a heat pump so is an extra charge for gas. The standing charge for electric is ignored in the calculation since it is paid regardless of whether you have a heat pump or not. Also, note that in our case we have no dual fuel discount. If you have a dual fuel discount, you need to factor in if you would lose that by going all electric. Another consideration is whether you can save more by going to a cheap overnight tariff. I think not in many cases because you will still have a chunk of heating being used during the day at a higher rate. So I suspect that’s irrelevant in most cases: exception would be an extremely well insulated house that you could heat only overnight. In such a case, you can do much better with heat pump than the calculations here suggest. ## £200 per year for service/maintenance of gas boiler is based on personal experience. ### The price of a gas safety certificate is based on what I actually paid in recent years. I’m assuming you do 2 in 13 years. The cost is higher for landlords, as it is obligatory every year. ^This is the price I’m actually being invoiced. That is £8405, less £5000 grant, so I pay £3405. This is after shopping around a bit as many were about ~£2k higher. ^^ For electricity use of 2727kWh, this is the electricity for the heating and hot water only, not the total electricity bill. This is based on a gas boiler efficiency estimated at 80% (from sources online) and a heat pump efficiency of 340% (based on many sources including articles, forums, and youtube videos that people have shared after actually measuring it). 340% means a SPF (seasonal performance factor) of 3.4 or average COP of 3.4. I’m assuming 3.6 for heating and 2.5 for hot water, with a weighted average of 3.4. Dividing 340 by 80, that makes a difference of 4.25. Dividing the known 11588kWh for the last full year by 4.25 gives us the 2727 kWh. ^^^This is based on the quote I got for annual service, and some articles and videos I read ages ago (don’t have sources handy) and some comments on this forum. £150 per year is charged for service by the company I use, but I’ll only pay this the first few years to keep the guarantee in place. ^^^^ This is what I was quoted by Southern Electric (now OVO). Further notes: I’m assuming for simplicity there will be 0% inflation for the next 13 years and that gas and electric will remain at the same price for 13 years. If I were to value my time at a high amount (say £100 per hour) and then work out how many additional hours I spent on this project vs installing a gas boiler (10 hours extra maybe? : mainly learning about heat pumps, this forum thread and getting and following up on quotes), a chunk of the savings would disappear. (£1000 value of my time.) However, I’ve decided to ignore this in the calculation.