Memorandum 74
Supplementary evidence from the Institute
of Physics (IoP) following the evidence session on 23 January
2003
Are there any environmental factors, such as the
available solar resource, that might limit the deployment of PV
in the UK?
This question demands a complex answer, because
it involves the demand that is likely at different UK longitudes
as well as the solar input at each longitude, its spectrum according
to the mix of direct and diffuse sunlight, and the temperature
at each site which can affect the solar cell performance. There
is also the less quantifiable fact that the skies are often clearer
and cloud-free for longer periods at some times of the year, in
the far north of the country.
In my opinion, the shortest answer is to give
you the predicted performance of a 1kW(peak) crystalline silicon
solar cell array having 14% conversion efficiency, set at the
optimum fixed inclination for any particular latitude, for various
UK locations, North to South. This is based on EU data for the
solar irradiance:
Lerwick: 724 kWh per year
Inverness: 773 kWh per year
Edinburgh: 802 kWh per year
Manchester: 843 kWh per year
Northampton: 854 kWh per year
Southampton: 931 kWh per year
This variation indicates that there is indeed
a valuable solar resource even in the North of the UK. It is possible
that the value of the resource may be much higher when it is considered
together with the local demand for energy and the cost of other
energy options there.
March 2008
| 
