Pompeyexile Since the introduction of solar specifically, I hear people talk about when installing any sort of heating system other than a gas boiler about payback etc and ‘ooh it costs so much you would never get your money back or it would take years’.
I think it depends on the alternative to your action. The alternative to no boiler is no hot water/heating, but If you have a boiler and get a more efficient one, then you might be more interested in ‘payback time’.
With solar PV the alternative is power from the grid, so people tend to look at payback time as the main factor (the others being environmental, psychological etc.).
DavecUK Please correct it…I only posted from quotes I’ve had and information about the equipment gleaned over 7 years plus my own circumstances.
I have had solar panels installed 4 months ago, so I can give you some real-life information rather than estimates. My system has 12 panels (capacity is 4.5kw) and I also have a 7.2kWh battery. The total cost was £9,825 (£5,245 for the PV and £3,977 for the battery - got it via Solar Together group buy scheme). Yesterday was a sunny day and solar yield was 22kWh. Today we hardly saw a ray of sun so the yield is only 3.4kWh. The total yield for March has been 278kWh (with a few days to go). The yield in February was 284kWh, January was 204kWh. We didn’t have the panels during the summer months, but obviously I expect it to produce considerably more. I have not yet had any payment for energy I export to the grid, but I have a pending request with a supplier that currently pays 6p per kw. Eventually I hope to move to Octopus, which currently has the best export tariff at 15p per kw.
Payback time is very hard to predict. We still don’t know how much we will save, and the numbers will change. We are currently on a fixed rate till October, then that will end. We don’t know what the prices will be in November, let alone in years to come. Appliances efficiency may change in the future. We might have an electric car. It’s hard to predict what will happen tomorrow, so how can we know what will be in a decade? If we save £80 per month, the system would be ‘free’ in ten years. If we only save £40 per month, it might be 20 years before ‘payback’.
Although payback is definitely important, and I doubt if I would install solar if I could see into the future and know that buying energy from the grid would be better economy, I still think there is more to it than just payback time. I like the idea of getting energy from the sun, which would otherwise just be wasted. It just makes sense and makes me feel better when the sun is out and I can bake bread/roast coffee/wash cloths/dishes with energy hitting my roof. I like the fact that it’s renewable and environmentally friendly. I like that fact that it reduces my reliance on the grid, so if there is war/crisis/greed/whatever and prices will stay high or become higher, I have this little shield and I’m buying less from the grid.
It’s not that I’m not hoping for a good ‘payback time’, but I look at it slightly differently than be all end all. On day 1, the system cost me X. Every month that I’m paying less for electricity, the cost of the system to me reduces. So even now, 4 months after I got it, it’s already a little cheaper for me to have it than it was initially. In a few years time it would be considerably less. Eventually, I do expect it to cost me nothing, and hopefully it will still be there on the roof and produce free electricity on nice sunny days. And if it doesn’t - then I’m sure it still won’t be my worst financial decision. Probably not even close.
