Here a report from the USA, I'm not sure how to read the results:http://www.uspref.org/images/docs/SC_ITC-Payback_July_12_2012.pdf
How are installed systems of renewable electricity generation influencing the electricity prices in the UK?
From what I've heard some years ago a 10-15 % share in a national electricity market makes renewables a price killer, non-renewable electricity investments becoming dead socks.
This share has now been achieved in the UK, most international energy companies specialised in non-renewables have lost interest in the UK's non-renewable electricity market
(Eon, RWE, SSE, etc...).
Unless heavily subsidised like the Chinese atomic power plants. At home - in China - these new atomic plants have been put on hold. Not worth it. Existing sites will be finished but new ones not financed, not being allowed, So the press.