One of the more bizarre aspects of the Feed-in-Tariff is that electricity producing photovoltaics are being used to power immersion heaters for hot water tanks. The "correct" technology for this task is the solar thermal panel, as these are much more efficient in converting sunlight into hot water. They are cheaper to install and they do it directly - or more directly than PV will ever do.
• 1m2 of solar thermal panel will produce around 500kWh of hot water per annum. Installation cost around £1500.
• 1m2 of solar PV will produce around 100kWh of electricity per annum. Installation cost around £700.
• Put another way, hot water powered by solar thermal is around half the price of hot water powered by PV.
Yet such is the distorting effect of the feed-in-tarrifs that people are now thinking of using PV for domestic hot water heating because they can't think of anything else to do with the surplus electricity produced on sunny days. Around 90% of the tariff is available just for producing electricity, and its easy to end up with a system that is oversized for purpose when the weather is right. On hot sunny days, you just don't need much in the way of electricity, so heating a hot water tank makes sense. And if you install more than 15m2 of PV on your roof, then you should be producing enough power to heat your domestic hot water, at least on a par with 3m2 of solar thermal.
So perversely, the way the feed-in-tariff is set up, one of the losers is set to be the solar thermal industry.
It makes senseBut only in terms of the strange Alice-in-Wonderland economics of feed-in-tariffs