PortafilterProcrastinator Get the loft conversion. I’m SW facing but could only put solar on the garage roof, my others are obstructed. The most I could put is 8 panels. However with the feed in tariff’s now not being worthwhile, you really need a battery. assume a normal 3.8kW ish system and decent sized battery, it’s probably around 13-15K. The solar Panel companies say you will generate around 2800, so say 3000kW under ideal conditions. I would imagine that would be unlikely to ever be met., so assume 2300kW per year as being more reasonable, that’s around £690 per year..
It seems like a 19 year payback…although you would need to keep the panels clean which would cost every year or output drops. The inverter would have been replaced once and nearing end of life 2K ish to have a new one put in….battery pack would have been replaced at 12 ish years 8K replacement cost. Plus you would be nearing the panels lifetime. So you’re still out around 10K and you are looking at a replacement system soon.
Even with the max ideal output, I don’t think it will they ever pay back apart from being cost neutral at best, they are going to be like endowment mortgages.
A loft conversion on the other hand, in the right property and location, can not only give extra space and enjoyment, but also increase the value of your property.
