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.