Spanish nighttime solar energy fraud ...The Ecologist | 16th April 2010
In the month that renewable energy incentives are introduced in the UK, Spanish authorities are investigating companies who claim to have produced solar energy at night ...
According to government data, between November and January, in the middle of winter,the electrical system received 4,500 megawatts / hour produced by solar plants between midnight and 7:00 a.m., plus another 1,500 between 7:00 p.m. and 11:00 p.m.
How were these megawatts generated?According to early indications, some photovoltaic developers could be using diesel-fueled generators to generate electricity, as the premiums are 436 euros per megawatt. = AU $ 708.11 ... 
Here is the Google Translation of the article.
You too can generate energy with your solar system at night, all you need is an 850 million candlepower WWII era searchlight, now available for rent.
And ... There are so many fees, taxes, add ons, etc to power bills here in California now it is actually cheaper to generate your own electricity running a diesel generator than it is to buy it from PG&E. Anyone have a used diesel-electric locomotive I can buy?
