Efficiency or cost per watt - which is most important?
Posted by Graham Eastwick on 2 March 2009 at 1:56 pm
The development of thin film photovoltaics (PV) is progressing fast. It's still not as efficient as crystalline silicone solar panels, but I have read of projects using thin film technologies from single roofs up to large “solar farms” with capacities in the region of 40 MW.
Crystalline solar panels can reach efficiencies of up to 20 per cent in production these days (which means it converts 15 per cent of solar radiation into electrical energy). Thin film is currently achieving efficiencies of between 6 and 12 per cent. Is this important or is it simply the cost per watt that matters?
If you have plenty of roof space or land then I would think that the cost per watt is the key factor when deciding how large a solar array to install. Thinking further, thin film technologies are said to perform better under overcast diffuse light so actually it is the cost per watt-hour that is the key factor.
In the UK we have quite a lot of diffuse light on cloudy days, so perhaps thin film PV is going to be a good technology for the UK market.
I would be interested in your views on this.
If you have a question about anything in the above blog, please ask it in the comments section below.
6 comments - read them below or add one