I cant support the building of ever more gas burning plant, the gas is in short supply and is imported from or via unstable places.

The answer is more wind and more solar generating capacity, a bit more hydroelectric and more storage. A large new pumped storage scheme is proposed in Scotland, at Coire Glas. We will still need some natural gas capacity for the foreseeable future, but the aim should be to reduce this and not to expand it.

Because older houses don't have the necessary insulation unless the homeowner can afford to insulate their house on top of the heat-pump costs. An Electric Combi-boiler wouldn't require new pipe work, radiators etc. Plus they wouldn't be affected by the outside temperature.

David Cieszynski said:

Because older houses don't have the necessary insulation unless the homeowner can afford to insulate their house on top of the heat-pump costs. An Electric Combi-boiler wouldn't require new pipe work, radiators etc. Plus they wouldn't be affected by the outside temperature.

Extra insulation isn't needed for a heat pump per se - it's just that it all becomes much more affordable if the heating load (and flow temperatures) are reduced - regardless of the heat source. Many heat pumps are perfectly capable of producing high flow temperatures (e.g. latest Vaillants can run at up to 75 degrees - compared with around 60 degrees to keep a gas boiler in condensing mode) but that's usually avoided because the COP drops to something horribly low and it gets too expensive to run - even though COP is still significantly above 1.0.

Given electricity is about 4 times the price per kWh compared with gas, heat pumps need a decent COP to break even - low flow temperatures and large emitter surface areas (e.g. underfloor) are just a means to achieve that.

By comparison, resistance heating has a COP of 1.0 at the very best - so simply switching a gas boiler for an electric combi would seem to be taking the worst possible case for a heat pump and making it slightly worse. The only positive I can see is possibly a slightly reduced capital cost - but that would soon be forgotten with the quadrupling of energy costs.

   - Andy.

David Cieszynski said:

I also think electric combi-boilers should be considered for older houses are heat pumps aren't the solution for the older housing stock.

Only if you want to bankrupt the unlucky people who have them installed.  Electricity is about 4 times the price of gas, and they can't sensibly work on off-peak electricity.

You might as well give them a new fireplace and tell them to burn £5 notes in it.

If a heat pump isn't going to work, fit modern high heat retention storage heaters instead.  At least they can run on Economy 7.

Heat pumps aren't cheap to run, the only way to make electric heat sources economically viable is to switch the green tax from electric to gas for domestic properties.

Here's a novel idea. If wind and solar are so cheap (as we are constantly being told,)  then why not remove all subsidies from them and let them stand on their own 2 feet  in the mktplace against fossil fuel based energy?

Then, let us see how many jump on the renewable bandwagon when the horses have been taken away.

After all, what could go possibly wrong? Might the emperor not be wearing any clothes after all?

David Cieszynski said:

I also think electric combi-boilers should be considered for older houses are heat pumps aren't the solution for the older housing stock.

Two problems: (1) it would be cheaper to supply a pile of fan heaters; (2) the electrical installation might not be capable of supplying such a large sustained load.

broadgage said:

A large tidal power plant has frequently been proposed in the Severn estuary, near me. I think that the NIMBYs won, with the great increase in natural gas prices, the idea should be re-visited.

Not a bad idea.

I suspect that there are very few viable sites in UK.

There is also the option of thermal storage charged 'off peak'.  GEC made a range of nightstore boilers in the 1980s that charged overnight and ran wet systems in the day.  At the time overnight prices were about half of day prices.  These days the charging could be dynamically controlled to optimise charging costs.  A cost cop of at least 2 could easily be achived compared to day usage and I suspect in practice it would probably turn out between 3 and 4 depending on weather and generation mix.  Flow temperatures would be unchanged minimising costs.  Just another option.....

Running an immersion heater over night might be an economical way of obtaining domestic hot water (supplied by PV during the day is even better), but I find it hard to believe that sufficient hot water could be stored for heating purposes.

I find it hard to believe that sufficient hot water could be stored for heating purposes.

Depends on your heating load of course (and the weather), but my 500l thermal store, when heated by the log burner for about 4 hours, will then usually keep the rest of the hose toasty (via UFH) for the remainder of the 24 hours without problem, as well as supplying a bit of hot tap water.  I do have an unusually low heating demand though (thanks to lots of insulation, triple glazing and so on).and heat from the the log burner itself will have removed the heating demand from part of the house for part of that time, but the numbers may add up well enough in some circumstances.

  - Andy.

I find it hard to believe that sufficient hot water could be stored for heating purposes.

Depends on your heating load of course (and the weather), but my 500l thermal store, when heated by the log burner for about 4 hours, will then usually keep the rest of the hose toasty (via UFH) for the remainder of the 24 hours without problem, as well as supplying a bit of hot tap water.  I do have an unusually low heating demand though (thanks to lots of insulation, triple glazing and so on).and heat from the the log burner itself will have removed the heating demand from part of the house for part of that time, but the numbers may add up well enough in some circumstances.

  - Andy.

AJJewsbury said:

I do have an unusually low heating demand though

Yes, you put the rest of us to shame.