A secretive Silicon Valley start-up is coming out in a big way by announcing that they going to build the largest solar farm in North America.

The Canadian Ontario Power Authority has purchased a solar farm from OptiSolar that will spread across 365 hectares and will supply 40-megawatt.
On a sunny day the so called Sarnia project will provide electricity for between 10,000 and 15,000 homes. The world-wide largest solar farm that is in operation is in Germany. It delivers 12-megawatt. The Germans work also on a 40-megawatt farm.
More details on VentureBeat and the Star. See also the OptiSolar site.