Air Sourced Heat Pump.

No, Andy, I do not have the wrong mindset. Yes, you can do all these things, and run the heating 24 hours a day and all the rest WITH A NEW BUILD. We have 30 million or so "old build" properties to manage, and none of your ideas are practical or affordable. Even the cost of running say 3kW 24/7 would bankrupt many people and the electricity system COULD NOT DELIVER IT. Have you ever tried to retrofit concrete floors in a 30s semi, or an older block of flats? Underfloor heating must run 24/7 to be much use due to "the time constant" I mentioned in my design piece. Getting a reasonably sized building to 3kW of loss is very difficult, try the calculation yourself, I was involved in a building (actually a Church hall) built like this idea, it cost £2.2 Million, and costs a considerable amount in energy despite having a lot of PV (10kW) solar collectors for hot water, and tons of insulation. It also has 50kW of gas boilers for when the weather is "inclement", and more still for hot water. Because it has underfloor heating it must be run 24/7, It costs a small fortune to run, although the Electricity bills are usually slightly negative. The gas and maintenance bills are not small, but it "green" and Energy class A. Its floor area is not much more than a number of large houses (Victorian) nearby. The heating and ventilation control systems still do not work correctly 4 years later, and the heating, etc "Consultant" has ceased trading to prevent bankruptcy. The only part to budget and works properly is my design!

No, Andy, I do not have the wrong mindset. Yes, you can do all these things, and run the heating 24 hours a day and all the rest WITH A NEW BUILD. We have 30 million or so "old build" properties to manage, and none of your ideas are practical or affordable. Even the cost of running say 3kW 24/7 would bankrupt many people and the electricity system COULD NOT DELIVER IT. Have you ever tried to retrofit concrete floors in a 30s semi, or an older block of flats? Underfloor heating must run 24/7 to be much use due to "the time constant" I mentioned in my design piece. Getting a reasonably sized building to 3kW of loss is very difficult, try the calculation yourself, I was involved in a building (actually a Church hall) built like this idea, it cost £2.2 Million, and costs a considerable amount in energy despite having a lot of PV (10kW) solar collectors for hot water, and tons of insulation. It also has 50kW of gas boilers for when the weather is "inclement", and more still for hot water. Because it has underfloor heating it must be run 24/7, It costs a small fortune to run, although the Electricity bills are usually slightly negative. The gas and maintenance bills are not small, but it "green" and Energy class A. Its floor area is not much more than a number of large houses (Victorian) nearby. The heating and ventilation control systems still do not work correctly 4 years later, and the heating, etc "Consultant" has ceased trading to prevent bankruptcy. The only part to budget and works properly is my design!