Starting Solarcity

While Lyndon and Peter Rive initially started researching the SolarCity concept in 2004 after BurningMan, SolarCity began operations in 2006, with an official funding round of $10 million from Elon Musk on September 15th.

You can read a bit about the founding thoughts for the company here:

http://www.motherjones.com/environment/2013/11/lyndon-rive-solar-energy-elon-musk

 http://fortune.com/2014/10/09/lyndon-rive-solar-city/