James Dennin, Kapitall: Popular alternative energy stocks like Tesla and SolarCity have had a volatile earnings season – will they stabilize? George Clooney got rid of his Tesla (TSLA), perhaps one of many reasons why the company's shares have fallen. Meanwhile SolarCity (SCTY)went down around 17% after reporting disappointing earnings – despite finding a new friend in the form of Tea Party Republicans hell-bent on bringing down monopolistic utilities. Read more on Alternative Energy from Kapitall: Two Clean Energy Stocks That Can Handle the Spotlight Which begs a question: is it a simply a tough week for alternative energy stocks? Or a sign that the chickens have come home to roost for these trendy companies, many of which have incredibly high valuations. CEO and Chief Investment Officer of Vilas Capital John Thompson believes the latter. Skeptical about Tesla from the outset, he sees huge problems with the product, and is unsure that the cost of the batteries will ever come down enough to make Teslas into affordable, mid-market cars. In a recent interview with Kapitall Wire, he said, "The biggest [Lithium] deposit is in Bolivia, and the President of the country wants to create a kind of OPEC…. Extract what they can. But [Elon Musk] said on the conference call, once they hit four to five hundred thousand cars a year – they’re going to be consuming half the world’s lithium supply. It’s a big problem in the long run…" But it must be said that Tesla is still a very young car company, with revenue increasing over eight-fold this year. Even if trouble like anecdotal evidence of car fires is unflattering from a PR perspective, these sort of issues are hardly unusual for a car company. And it's hard to imagine anyone would care if Brad Pitt didn't like his new Ford (F). Younger companies like Tesla are often more volatile on the stock market, and the same holds true for green energy firms like those operating in solar power.But not all solar companies have had a disappointing earnings season like SolarCity. Canadian Solar (CSIQ) announced that they are the first major solar power company to return to the black after two years, and upgraded their expectations for next quarter's sales. So is the volatile, unpredictable and broad industry of alternative energy still worth watching? We've compiled a list of stocks operating in solar and other green energy markets for you to consider.Click on the interactive chart below to see analyst ratings over time. Do you see investing opportunities in these alternative energy and environmental stocks? Use the list below as a starting point for your own analysis.