Let's face it, from an investing standpoint there's no way to feel good about a sector that dropped 70% last year, except maybe if you got out in 2007. But most investors didn't get out of clean energy then.

"You could say that it was up 58% in 2007, so that a drop of 70% is not as bad in 2008. But at the end of the day, nothing is solved. Nothing makes a person feel good, and there's nothing I can say to make a person feel good. It's human nature to go into something when it's way up," says Rob Wilder, CEO and founder of Wildershares and manager of the WilderHill Clean Energy Index (ECO). The firm's other indexes include WilderHill New Energy Global Innovation Index (NEX), WilderHill Progressive Energy Index (WHPRO) and Wilder NASDAQ OMX Global Energy Efficient Transport Index (HAUL). InvescoPowerShares has some funds that track Wilder's indexes.

As an indexer, he reminds me in a recent chat, his job is not to time the market or recommend when investors should jump in or out of any part of it. He's trying to capture the performance of the clean energy sector, whatever that may be. And it's no surprise that Wilder believes holding a basket of stocks in a particular industry is a better way to mitigate risk and improve return as a function of risk than building an active portfolio.

But he admits this bear market is worse than most. While Obama is increasing public funding for renewable energy, the credit crunch has meant bank loans have dried up for many clean energy projects. The lack of private funding means 50% of the wind projects proposed now might not get done, Wilder says. Add a plummet in the price of crude oil to around $40 a barrel to all that and it's easy to see why, among investors, there's a crisis of confidence in clean energy that's even bigger than how they feel about the market as a whole.

Wilder is quick to remind that the market won't stay this way forever. "I don't know how many times the world has to end for people to know the world doesn't really end," he says.

Will the U.S., for all intents and purposes, give up on clean energy again, much the way we did after the 1970s oil crisis ended? I don't know, Wilder responds.

But he points out that things aren't the same as they were 30-plus years ago. Although wind projects do need a lot of credit to get going, today wind power is more reliable and cost competitive with natural gas and nuclear power. Solar power is still expensive, but with state subsidies and foreign investment it also is becoming more affordable. Energy efficiency is getting better. Electric cars are now a real possibility.

Plus, who thinks oil is going to stay at $40 a barrel? OPEC really needs 70 bucks a barrel, and at some point China and India will increase demand, Wilder says.

"On the other hand, Greenspan has called this a once in a half-century event, and it sure feels that way," Wilder says. "You can look at this as a huge buying opportunity, while others say this is part of a longer-term downward trend. I don't know which side is right."

What do you think?