It was earnings season last week, and a look at some of the results posted by some of the leading clean energy companies provides a fairly accurate picture of how this crucial industry is fairing in the midst of this punishing recession.

Take First Solar, the Tempe Ariz.,-based maker of solar panels, which tripled revenues during the first quarter 2009, announcing net income last week of $164.6 million on revenues of $418.2 million. The company brought in $46.6 million in net income last year on revenues of $196.9 million.

First Solar clearly did well but was quick to warn that despite its stellar numbers, it expected the market to stagnate, at least over the coming year, pummeled by the economic crisis. But on the upside, the company added that the Obama stimulus and the $100 billion allocated for clean energy would, in the long-term, help make the U.S. an attractive and growing market.

Also racking in profits during the first quarter was Danish wind turbine manufacturer Vestas Wind Systems, which reported net profits of $73 million (56 million euros) for the first three months of 2009, up from $43.8 million for the same period last year. But despite the positive earnings, the company, citing the poor economy, said it would slash 9% of its workforce.

Not all companies are in the black. EverGreen Solar, a Marlboro, Mass.,-based maker of silicon wafers for solar panels, lost $64.3 million during the first quarter, blaming the loss on a write off of a $43.9 million loan to a silicon supplier.

Interestingly, the company during its earning call said it was negotiating with a Chinese company to relocate some of its manufacturing capacity there. The move could help the company lower production costs at a time when margins are getting tighter.

The sector, looking at the earnings of First Solar, Vestas Wind Systems, and EverGreen Solar, is for the most part healthy. In the case of First Solar and Vestas, both were able to turn a profit.

While, overall the outlook remains positive — just last week French oil giant Total announced that it invested an undisclosed amount in U.S. biofuel maker Gevo — overall companies remain pragmatic, aware that at least for the next year that demand for their clean energy products are likely to falter.