21-06-2013, 02:50 PM
There is, or possibly was, something like this available commerically. Can't find it online at present.
You need to do the sums to see if it's worthwhile. Taking my own PV installation. It's 2kWp and gives about 1600kWh/year. I don't know how much I actually use but let's take the usual 50%. That means there's 800kWh I'm exporting that I could possibly use to heat water. Since I use mains gas for water heating that's perhaps £30/year if I can use all the surplus. On a sunny summer day when I've got most surplus it may well be more than I can use.
If you heat your water with more expensive fuels then the return is better.
You need to do the sums to see if it's worthwhile. Taking my own PV installation. It's 2kWp and gives about 1600kWh/year. I don't know how much I actually use but let's take the usual 50%. That means there's 800kWh I'm exporting that I could possibly use to heat water. Since I use mains gas for water heating that's perhaps £30/year if I can use all the surplus. On a sunny summer day when I've got most surplus it may well be more than I can use.
If you heat your water with more expensive fuels then the return is better.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
