I've previously written about the possibility of using the output of
photovoltaic panels for heating applications in circumstances where
traditionally solar thermal (evacuated tube or flat plate) panels
would be used:
PV For Space Heating,
PV, ETs and Flatties
and, slightly less interestingly,
Solar By Area.
Since then the price of PV has continued to drop.
At the moment Navitron, for example, are doing
Kinve 235 W panels
at a fraction over £0.57/W (incl. VAT) compared with another
supplier's £0.74/W + VAT at the beginning of the year.
In the mean time
I've been fiddling around doing a calculator web page to try
to explore the trade offs in systems which combine solar thermal
with a heat pump driven by photovoltaic panels.
I'm not happy with the design of this yet
(it works as intended but it's difficult to get anything very
insightful out of it) but playing with it a
bit did show over how wide a range of operating conditions the
costs of output power of PV and solar thermal are similar.
This page is, therefore, a simplified version of that
calculator designed specifically for comparing the cost of
power from PV and solar thermal.
More...