An interesting case in California begs the question: Which one is greener, trees or solar panels? Neighbors Richard Treanor and Mark Vargas were locked in battle because Treanor's 35-foot oak trees, planted over a decade ago, shaded Vargas' solar panels. In this case, the court ruled in favor of the solar panels because of California's Solar Shade Control Act, a law passed in 1979 and not applied until now. Treanor was not fined but has until March 28 to cut down his trees. It's a tough call for me but given that Vargas has a $100,000 solar panel system in place, I think it's the right one.