E Ireland wrote:
Surely the objective is to drive electricity prices so low that heat pumps are not worth it anywhere?
The reason that heat pumps are becoming more common in Germany but not in France is that retail electricity rates in Germany are essentially double those in France.
So per kWh of delivered heat a h eat pump in Germany will cost about as much as a resistive heater in France without considering the collosal capital costs of the heat pump compared to a simple fan heater.
It would be nice to have low electricity prices - from a clean source - so you don't have to care about efficiency. But they're not building LFTRs near me, so that's not going to happen.
If the EPRs deliver at 90p/KWh to the grid, that's still 15-20p to the consumer, or about 3 times the price gas, which is why heat pumps are slightly cheaper to run than gas, but not enough to make the investment worthwhile unless you're off gas grid.
The problem with significant property densities and ground source heat pumps is they can freeze the ground solid during a cold winter which has some major implications for both local plant life and for underground utilities (you start to get frost heave and similar problems)
If they're badly sized. Like nuclear plants get flooded or blow up - if they're badly designed or operated.
My case was a ski resort. Freezing the ground could have been designed in to help extend the ski season - but that's an exceptional case.
I'm not sure why you think solar + storage will never be competitive with retail electricity. People said the same thing about solar even 5 years ago, and now it's cheaper than retail in Italy, Spain, Germany (and even the UK at a 3% discount rate). With falling battery prices solar + storage will be cheaper than retail prices by 2020 in the above countries.
If it were cheaper than retail why does it still rely on huge subsidies for new installations?
Good question. Solar is cheaper than retail electricity, but you have to export some of it where it's not worth much at all. So the current business case without subsidy would be slightly positive in Spain or Italy but negative in the UK.
Add in storage and the amount you have to export goes down, and you can export it when demand is high - it's worth a lot more.
But it is interesting (say the Economist in me - boring says the Engineer) why there are so many south facing roofs with no solar panels, despite the current subsidy regime making it a very attractive investment.
Solar+Storage is especially worthless in northern latitudes because it will produce almost no power for several months of the year.
No - the consumer doesn't necessarily care about the winter. Being able to export when the price is high and not import, for 8 months of the year, makes the business case. In winter, the consumer can still import electricity at night and sell it at a higher price in the day.
That does create a capacity utilisation issue for the CCGT operators, who have to idle their plants for 8 months. If I care about that, then I'll get myself a fuel cell module to provide heat and electricity in the winter.
It is worth noting that ASHPs will only reach COPs of 4 when the temperature outside is above freezing.
If its -10C or -20C outside then they will not do that much better than a resistive heater while having significant maintenance requirements.
Which is why they make sense in most of England (if you don't have gas), Spain and Italy, but not in Germany or Scandinavia. Plus the fact they're easy to retrofit and some modules can be reversed for air-con in the summer, which would be useful in England for about 4 days in the year.
Air to water heat pumps are more useful still as they can use night time electricity to heat the thermal mass of water.
(My one reaches a COP of 5.5. But it's only for heating a pool in the summer.)