A conventional solar cell.

The mood among people involved with the solar energy industry is surprisingly optimistic these days, given that the industry is suffering badly from the recession.

Even with tax credits meant to stimulate the solar industry a number of big solar farm projects announced last year are in danger as financing dries up. For example, one fast-growing solar company, which is supposed to supply the panels for a 550-megawatt solar farm in California, recently had to lay-off nearly half of its work-force, according to the LA Times. It's also having trouble financing an expansion of its assembly facilities.

The problem, according to venture capitalists, entrepreneurs and researchers involved with solar energy, is that the tax credits designed to promote investment in solar energy aren't working--no one is making any money to tax, even the banks that would have provided financing.

But hope is in the air: the stimulus bill now before Congress could change everything. Modifications to the tax credits could allow companies to get money from the government even if they're not operating in the black this year. What's more there are billions of dollars designated for solar research (the exact numbers haven't been settled yet).

Much of the talk at an informal meeting of solar industry experts this week in Boston revolved around how to make the incentives better. One option is something called a feed-in tariff, in which a certain price for power from solar panels is guaranteed, and paid for from a designated fund. This provides incentive not only to make solar panels, but to install them and make sure they're working. Such maintenance can make a big difference. Tonio Buonassisi, a professor of mechanical engineering working on solar cell research at MIT said that ice and snow accumulating on his home solar panel array this winter has slowed power output to a trickle. He said that if he were guaranteed income from the power, he'd be up on his roof cleaning them off. "If your printing money on your roof, you'll be up there making sure it's working."