SteamyTea

Measure the angle inside.

That scenario is well understood and managed. The grid was never in danger of collapsing. This is to do with the local grid, not the main infrastructure. You would not run your immersion heater of your lighting circuit, so why expect the local DNO to supply reliable power to your new house free of charge. National Grid and the DNOs are private commercial companies, like Tesco and the local pub, they don't give stuff away.

If we woke up tomorrow and there was no gas and all transport was electrified, then yes. But as this is going to be planned phase out of fossil fuels, then over time the grid will be adapted to to this into account. I did some calculations a while back to see just what could be done on any given day if we wanted to charge cars up. If we allowed willy nilly charging at any time we like, then 3.5 million cars could be charged, if we limited to the E7 window, then 7.5 million. Now a car is going to draw about 30 Amps on an overnight charge, and take around 15 kWh. A heat pump in an average house will draw about 7 Amps, and take about 20 kWh on a very cold day. So less power by a factor of 3, and it is power that the grid is concerned with, the extra energy, that cars and homes needs us just a matter of more generation, that is like putting extra fuel in a car 'just in case' you need to drive faster for a bit longer. With 60 GW of generation available to the NG, most of that capacity is already there, and more added every day. We have now got rid of coal fired generation (just about) and no one noticed. We also have reduced nuclear generation, and no one noticed. But 1 wind turbine in a field, and there is outcry.

It is easy enough to run the numbers and see what comes out. While the performance in mid winter may not be good, all months except December and January, PV could me a major contributor to the energy demand of a heat pump. The trouble is that matching the times that PV generates in with the times that you need the HP to run. This is not a problem for DHW as that is stored, though parasitic heat loss can eat away any advantage on a badly designed system. Space heating is a lot harder as you need a way to store the energy for later. This is usually done 'in the slab', but would mean that you may get an unacceptably high temperature when you don't want it, or the HP is cycling too often. So what would normally happen is that you have to work with averages and accept that at some times you are importing energy, possibly and a high cash price i.e. 6 PM. We are now getting fairly close where a combination of PV, Battery Storage and HPs together with some software could probably make a very cost effective system.

Never been to bed with an ugly one, but woken up with a few.

@joe90 has about 200 m2 I think and his ASHP is 4 or 5 kW. His DHW demand is lower than most (2 of them) and he is in a mild part of the country. I think his ACH number was around 1.5.

Is that 1807 kWh the monthly heat load figure, or does it include DHW? Assuming just the heat load, divide it by the number of hours in January (31 x 24 = 744 [hours]). Divide the kWh by the January hours and that will be the power needed. 1807 / 744 = 2.43 [kW] So about 3 kW is needed to keep your house warm and allow a little bit of headroom temperature changing and improved efficiency for the ASHP.

You need to get more PV on the boat and fit a water source heat pump.

Is it the actual cells that fail, or the protection circuit?

Have a look here: https://www.heatpumps.org.uk/manufacturers/ There is a large green one, can't remember the name of the company, but been told they are alright. Kensa make GSHP down here, but they buy in the compressors.

That is my experience with my timber frame, 1987 vintage. I even have that sort of temperature rise in the, in the unheated parts, in winter, usually more. The front of my house is SW facing, so the last few days have been tough. I stuck tin foil on the inside of the bedroom window as a temporary measure. Works brilliantly and only cost a quid. Last two nights have been killers. For only the third time in my life I had heat stroke yesterday, got home just wanting to sleep, could I (expletive deleted).

Cornwall Council seem to think that everything must be geared to tourism and hospitality, or less that 15% of the counties economy (this number varies slightly, will be higher this year). The last working mine, South Croft, stopped producing anything of note in the late 1980s. There has been talk about reopening it ever since, but the council keep putting obstacles in the way. Now SC is next to the Hartlands World Heritage Site, as if we needed yet another mining museum with 10 quid sandwiches.

I think you misunderstood my point. We can capture all the 'bio' waste we want, but compared to our current usage, it is tiny, which is why we don't do much of it at the moment. Regarding the farm waste and other sources, a mate of mine commissions these types of units and there is a lot more to it than just letting the waste ferment, then capture the gas and either inject it into a gas grid (it has to be of the correct calorific value, not pollute existing equipment...) or burn it in an engine to generate electricity.

This morning on Radio 4 there was something about gas smart meters not being able to work with hydrogen. Big deal, if the only challenge was swapping a meter over then life would be easy. In education, there is often a saying that we are education people for jobs that don't exist yet. This is total bollocks. Changing a name from typist to word processor operator is not a new job. A person who used to be called an attention seeker is now called a YouTube star. Not exactly new. There is way to much bullshit spoken in some quarters, and there seems to be an impression the more people that follow your belief, the more right you are, as long as you shout about it. Did McLaren invent the ventilator, no, and did they make any in the end?

Part of the problem is that we don't produce that much, and with new waste legislation, we will produce even less. But BIFFA have some numbers about what they are doing. 90MW of installed capacity, 530 GWh/year generation. So a capacity factor of 68%, which is pretty good. The UK generates around 75 TWh of electricity a year. So BIFFA supplies about 0.7% of the UKs energy. We can all easily save 1% by turning the DHW temperature down by less than 1⁰C. There is also the problem if CO2. LFG is about 40% CO2, which is not combustible, so you either take a hit on the boiler efficiency or you have to remove it. I don't think the strategy is either/or. That is just they way it gets reported. If it was, then we would be building nuclear power plants by the dozen, installing 1000s if large wind turbines and filling unused space with PV, then swapping out thermal boilers with electrical boilers. Would possibly be the fastest way to reduce GHG emissions. But we have legislation in place that near enough stops all that. And the cash price would be very high circa £80/MWh wholesale. Almost double what we pay today. Though 8p/kWh wholesale, it is really still very, very cheap.