@ghaynes Excellent write up.
I looked into a similar setup a couple of years back, and again recently with energy price rises.
I think one of my key takeaways is that PV, ASHP and a battery all appear to be underwhelming investments on their own, but as a system they deliver a benefit that's greater than the sum of their parts (so I can genuinely use the word "synergy" here without it being corporate buzzword bullshit). So one my my key findings was that I'd probably wanna drop the cash to get them all done, rather than doing it piecemeal.
Another takeway was to disregard analyisis from people that assume the battery is worthless the second its 10y warranty runs out. Home batteries, especially LFP ones are temperature-controlled and charged and discharged gently, so likely to experience very good lifespan and low wear. Personally I'd hope to get at least 20 years out of a reputable home battery.
A similar example is cars - my car has a three year warranty and would be a terrible investment if I assumed it broke after three years. Instead I assume it'll last the UK average of 15 years. Same applies to home batteries - the warranty is likely to be significantly less than the actual life.
My final takeaway is that it would be a little bit of a leap of faith / hobby project. Current lekky prices have made the ROI periods much shorter, but I think it's still up for debate whether you'd be better off investing in the stock market instead.
But a bit like buying home insurance, it would be somewhat of a safety net to cushion me against pessemistic future scenarios. So there's an intangible value there in being able to damp out energy price swings.
All in all, I wish I'd have been able to get one when I looked into it a couple of years ago. The ROI was pretty neutral back then, but I'd have been laughing all the way to the bank now...
I looked into a similar setup a couple of years back, and again recently with energy price rises.
I think one of my key takeaways is that PV, ASHP and a battery all appear to be underwhelming investments on their own, but as a system they deliver a benefit that's greater than the sum of their parts (so I can genuinely use the word "synergy" here without it being corporate buzzword bullshit). So one my my key findings was that I'd probably wanna drop the cash to get them all done, rather than doing it piecemeal.
Another takeway was to disregard analyisis from people that assume the battery is worthless the second its 10y warranty runs out. Home batteries, especially LFP ones are temperature-controlled and charged and discharged gently, so likely to experience very good lifespan and low wear. Personally I'd hope to get at least 20 years out of a reputable home battery.
A similar example is cars - my car has a three year warranty and would be a terrible investment if I assumed it broke after three years. Instead I assume it'll last the UK average of 15 years. Same applies to home batteries - the warranty is likely to be significantly less than the actual life.
My final takeaway is that it would be a little bit of a leap of faith / hobby project. Current lekky prices have made the ROI periods much shorter, but I think it's still up for debate whether you'd be better off investing in the stock market instead.
But a bit like buying home insurance, it would be somewhat of a safety net to cushion me against pessemistic future scenarios. So there's an intangible value there in being able to damp out energy price swings.
All in all, I wish I'd have been able to get one when I looked into it a couple of years ago. The ROI was pretty neutral back then, but I'd have been laughing all the way to the bank now...