Hybrid ASHP / Heat battery option: thoughts appreciated.

NedS

Fink_Nottle said:

COP of > 6? Magnificent!

Yeah, that's relatively easy this time of year. What's perhaps more relevant is the efficiency when it's -2C outside, the heat pump is running constantly and you're struggling to maintain a COP of 3.
But I hope it highlights what you have already realised, that having an old stone walled property is irrelevant to achieving good efficiency - it just means it might take more energy to heat than a well insulated property but it doesn't matter what supplies that energy - heat pump, gas boiler, oil boiler, electric heater, log burner or whatever - it's all just a source of heat. The next time someone tells you their property isn't suitable for a heat pump, you know they have fundamentally not understood heat pumps (or the concept of heating a property).

Fink_Nottle

An update to this old thread in case anyone out there is also pondering about heat batteries.

Personally, I still think they're a neat solution, but I hit a bit of a problem: I couldn't find an MCS accredited installer who does them! I'm sure there are plenty out there, but not near me, and the big national installers seem to give them the swerve.

I therefore had a couple of options a) keep looking for an installer - and I'm sure that eventually I'd have got there b) revisit my ideas about where to put a cylinder. I went for b and had a lightbulb moment (well, my partner did) about where to put it, got Octopus in to do a survey, and they confirmed that she was onto something. Install is booked for next week.

One further thing: the survey was really helpful in flushing out some of my false assumptions about how all the components are rigged up. (e.g. the power supply is rather easier than I'd figured. Octopus spur off the meter, then run cable to the pump. The cylinder's power is then fed via the pump, the cabling running alongside the copper).

My takeaway for anyone keen on the idea of a heat pump, but pondering how to make it work for them, is to consider getting a survey. It's educational (and is often free / refundable if you decide against going any further).