DamonHD

By ensuring the that the system tells them just what they need to know to get there, and helps them along, assuming it's possible. ("Heat the house for zero cost with all the windows open when it's freezing outside" doesn't have a good solution!) And not expecting the end user to have a physics degree: "folk physics" seems to be bad in general.

By agency I mean "to make it do what the user need,s at reasonable cost" rather than necessarily "to understand each of the 50 control parameters". I had near neighbours who had a HP in new (badly built) social housing with no explanation on use, ending up with a ~£4k heating bill ~15Y ago. Agency would avoid that.

OpenTherm isn't open: I think you have to pay a lot to look at the spec and thus I haven't ever seen it. I suggested some time ago to LG and others that there should be a mandated basic common interface across all devices of a given type, but which does not prevent a manufacturer adding their features on top. Indeed this will be the final bit of my PhD research - how to give normal humans more agency with heat pumps than most ever had even with gas.

I am a bit late to this party, but my HP + smart TRVs (obvs!) combo seems to work well. I'm about to start a paper on my work showing that TRVs and retrofit HPs can work well, and one difficult area is 'comfort'. I am happy with daily temperature cycling and summer and winter, and not heating more than needed overnight for example feels like a win on energy and comfort (and I hope to be able to share experimental results to that effect), but huge numbers of people seem to feel that the only comfortable temperature is a rock-steady one at or above 18C... Which amused Prof Mackay then Chief Scientific Advisor at DECC, when told it by a senior boffin from BRE (I think) at a big meeting at the end of 2012. Mackay said that his family (including very young child) turned the heating up for a bit from 14C if they began to fell chilly. Anyway, am I the only one happy with daily temperature cycles?

5m between what and a boundary?

All this stuff is going to become more important to help delay or schedule substation upgrades, etc. And so there has been evidence gathering on what info should be collected and collated by whom, and who should be able to see that data: https://www.gov.uk/government/calls-for-evidence/improving-the-visibility-of-distributed-energy-assets

The DNO and others may well care about how many kWh you produce/export as well as peak kW or A because of their diversity calcs. At the very least it adds more noise to the industty settlement process. And I've been involved in NG/ESO and gov discussions about understanding where assets are and how they behave. You won't be helping! B^> Realistically, adding a couple of panels' worth of generation - ie a small chunk of a existing output - probably won't hurt anything. And I'm absoutely not going to show you this: https://www.amazon.co.uk/dp/B0CJFTBR41

Your existing system will have been signed off with the DNO, and possibly a FiT administrator, with a particular configuration and capacity. That is what you have permission for. Changes may require new permission or at least notification.

Our family of 3.5* in small end-of-terrace use ~6kWh per day excluding heat/DHW. *daughter at uni but with us on breaks!

If you add them to an existing system for which you are getting FiT then you should tell your administrator and they will scale down future payments from what your generation meter says to compensate, ie to only pay for the PV that went in under FiT. Also, in principle, you should tell the DNO, or ask first if you would go over 16A per phase, I think.

No footballs kicked in around in my garden, but they don't feel fragile, and have been up some years now. https://www.earth.org.uk/expanding-off-grid-PV-system.html#20160722

I use mine for an off-grid system, and they are functioning as a privacy screen as that wall is quite low!

FYI: https://wind-curtailment-app-ahq7fucdyq-lz.a.run.app/

But I cannot run the heat pump at all with the dregs of PV low generation in as agile way as with diversion. (I don't mind spilling to grid because it gets used to avoid gas burn usually at the moment.) I also avoid diversion when grid demand or carbon intensity is high, or frequency drops to which I respond within a minute. None of that agility is easy with minimum hp compressor cycles lengths and minimum power draw. Starting from fresh I and given that I *do* now have a heat-pump I might use a bigger electrical battery instead.

Yes, I believe it does even now, eg the Thermino loses heat at half the speed of the DHW cylinder even when much hotter, and at a rate comparable to the electrical batteries' self-discharge. I had the Thermino+Intasol long before I installed the ASHP. Given the rapidly falling price of electric batteries now cf when I started it would now make sense to consider additional electric battery (in particular to be able to cover the maximum power demand of the heat pump) instead of heat battery for new installations.

Not true for me. Via tight control using my Eddi, I regulate how full I let my Thermino get and choose whether to let it get full enough for its automatc cut-out to operate or not, which enables me to do things like this to reduce our grid exports around solar noon to be kinder to the grid: Full-week 15-minute con consumption and net imports for 2025-07 generated with sh script/storesim/load_profile.sh 202507. Full-week gross consumption and net grid flows for 2025-07. Times UTC. Data and other views are available. And there is about 30% heat capacity above the 58C point before that cut-out.

I'm heating by diversion so that doesn't apply.

I 'fill' my Thermino to ~80C which adds ~30% to the nominal capacity over the phase-change temperature.

Here was the set of talks (PDFs with some earlier audio/podcast versions)... https://www.earth.org.uk/Kingston-Efficient-Homes-Show-2025-Bitesize.html#Short

If we are going to electrify everything to achieve Net Zero then the DNO is going to have to deal with much bigger power demands in both directions eg from PV generation and EV charging. Upgrades will need to happen. I think that the DNOs accept so. It is not your problem to make that happen.

It is the DNO's legal responsibility to keep RMS voltage within bounds, as I understand it. My dad's PV used to shut down occasionally from overvoltages, being on a semi-rural weakish feeder. I believe that it got fixed.

FYI: https://www.earth.org.uk/note-on-16WW-mains-voltage-monitoring.html I regard anything below 235.5V here as a sag, and stop diverting PV to my heat battery within 60s if so... Rgds Damon

For the record our Thermino is doing just fine, helping us soak up solar PV in the middle of the day in particular and reducing how much DHW we need from the heat pump. https://www.earth.org.uk/note-on-solar-DHW-for-16WW-UniQ-and-PV-diversion.html An alternative these days is to have (more) electric/mains battery along with the heat pump to act as a store.

There is another 'bitesize' event in September: https://www.eventbrite.co.uk/e/bitesize-efficient-homes-show-tickets-1492300303379

To confirm: lots of research in the UK in the field (eg Energy Saving Trust, Energy Systems Catapult, others) has shown that there is simply no type or age of dwelling that can't have a successful retrofit, though some awkward cases will be awkward. And indeed making the retrofit by 2050 of ~20M UK gas boilers with (mainly) heat pumps work well is the topic of my research. FWIW I only replaced one rad when I upgraded to a heat pump at the end of last year.