By David StermanNEW YORK ( TheStreet) -- The road to a greener future has been a bumpy one for investors. Clean energy stocks have risen and fallen in tandem with changing government policies and wildly swinging fossil fuel prices. Yet the industry has made considerable inroads as industry revenue for solar, wind and efficiency companies have risen nicely higher in recent years. At the moment, investors are jumping back on the bandwagon of clean energy stocks. For example, the PowerShares WilderHill Clean Energy Fund ( PCX has risen +25% since late August. Yet even as many clean energy stocks have moved up sharply off of their lows, a handful of stocks remain stuck in the mud due to company-specific problems. Here's a quick look at five industry laggards -- at the end, I'll select the one most likely to rebound.