DamonHD

Fully insulating our homes and electrifying our heating *will* knock ~15% off the UK's current carbon footprint. On a slightly different note, and much smaller beer but still needs sorting and would be *very* easy to address, I'm trying to get Apple, Amazon, Spotify, etc, to do something about the the 99.9% of resources they are wasting polling RSS/podcast feeds: https://www.earth.org.uk/RSS-efficiency.htm

I am using the numbers from the original Heat Geek page / pump, a Mitsubishi Ecodan.

My model is purposely as simple as I could make it and is steady state, eg no thermal capacity, losses other than conductive, incidental gains, etc...

@sharpener"You could keep turning it down" is a bit of a straw man. 😀 My point here is mainly about tolerance (dynamic and static) of deviations from a selected preferred temperature. Yes, indeed, if you are too hot all the time then move your setpoint down. However, not all users of the same home have the same preferred setpoint or tolerance just to complicate issues, and each of us have our tolerance affected by things such as external weather, time of day, recent activity levels, ... I note that my daughter wants a set point far higher than I do, at a point where I am beginning to feel uncomfortably warm sometimes. And she is dressed sensibly! So our rooms have different set points: hard to acheive without zoning.

I have my research plan / confirmation report open right now, and I am putting "the effect that increased short-cycling on ASHP COP" in it right now... B^>

A key point which only became clear to me from a throw-away remark from one of the peer reviewers: the bad setback effect is forced by having rads only just large enough for the no-setback state. This suggests always at least slightly oversizing rads if you can.

I was just on an Elexon working group considering allowing domestic PV users to net exports and imports in any (settlement) half-hour, which would save the home a little money and would reduce settlement inconsistencies elsewhere in the system. One of my worries was precisely the perverse behaviour that it might encourage around the edges of HH periods, eg everyone 'using up' any excess export in minute 29 at once.

Proposed the last two for our local plan...

Looks horrible? Compared to (say) the horrible concrete tiles on my roof? I think solar PV on a roof is far far easier on the eye than a monstrous dangeorus polluting noisy SUV / 4x4 obstructing a road, just for one example.

Indeed: the conservation officer conversation around solar PV many years ago for a farm with listed buildings was about making sure that anything we did to the historic buildings should be reversible. In the end the conservation officer found a magnificent work-around that kept everything away from the historic curtilage, but still within the farm curtilage for the feed-in tariff!

My view is that any works to improve home energy efficiency etc (ie reduce climate harm) should be accepted by default, unless dangerous, illegal* or obviously antisocial. A chocolate-box townscape that has melted because of heat waves is no use to anyone. I've responded to government consultations to that effect. And the argument actually helped with conservation officers in the past. *This may included listed/conservation status.

Yes!

I had a paper published: https://www.mdpi.com/2071-1050/16/11/4710 TL;DR: when you are replacing a gas boiler for radiators with a heat pump such as an ASHP in a typical UK home and using weather compensation for the system, consider retaining TRVs in areas such as bedrooms, sunrooms or others with variable incidental gains, and also in low-occupancy rooms, as this should be a cheap and easy way to save more energy and improve comfort. You will still need to ensure sufficient flow and volume for the heat pump.

Ahem ... in summer!

I think that for much of the UK it could be made to work. MacKay did the sums to indicate that only at fairly high urban densities do you need to actively push heat back into the ground in winter. Also see for example: Geothermal pavements: A city-scale investigation on providing sustainable heating for the city of Cardiff, IK Makasis, Nikolas and Gu, Xiaoying and Kreitmair, Monika J. and Narsilio, Guillermo A. and Choudhary, Ruchi https://www.sciencedirect.com/science/article/pii/S0960148123011631 DOI:10.1016/j.renene.2023.119248 Quote: "Depending on ground conditions, 184–345 kWh annually/m road of heat can be provided. Geothermal pavements can reduce anthropogenic heat flux into the ground by 390 MWh/a. In low population density areas 100% residential demand can be fulfilled, overall 23%. Replacing traditional systems can reduce carbon emission by 75%." Basically much of Cardiff's home heating could be provided by shallow geothermal. And this mob looked at Cardiff because the geology is very very well studied. Rgds Damon