Musk provided the initial concept for SolarCity, which was then co-founded by his cousins Lyndon Rive and Peter Rive.[51][52] Musk remains the largest shareholder. SolarCity is now the largest provider of solar power systems in the United States. The underlying motivation for funding both SolarCity and Tesla is to help combat global warming. (…)

After reading philosophers Hegel, Schopenhauer and Nietzsche during his mid-teens, Musk briefly became depressed with the lack of answers to the large questions of life, such as the reason for existence. After coming to this conclusion, Musk decided that perhaps the reason for the lack of good answers was that mankind was not yet at the point to be able to ask the right question.