This week, we got earnings reports by both Energy Conversion Devices (NASDAQ:ENER) and GT Solar (NASDAQ:SOLR), two very different players in the solar space. Investors seemed impressed with neither. Let's try to figure out why the sparks aren't flying.

ECD's solar subsidiary United Solar Ovonic describes itself as "the leader in building integrated and commercial rooftop photovoltaics, one of the fastest growing segments of the solar power industry." Clearly, the segment isn't growing fast enough, because ECD only managed to generate $43 million in revenue in its first fiscal quarter. That's down 55% from last year and 17% sequentially, and nowhere near enough to cover operating expenses. Maybe ECD penned that business description last year, when the stock was trading at more than $80 a share!

Back in March, ECD stumbled badly, and the shares have since shed another 25%. Meanwhile, Yingli Green Energy (NYSE:YGE) is up 220%, and Trina Solar (NYSE:TSL) is a five-bagger. Even the diversified Claymore/MAC Global Solar Energy (NYSE:TAN) ETF is up 67% in that time, so ECD is having an embarrassingly bad year, especially in relative terms. Of course, the shares' underperformance partially stems from how obscenely overpriced they were last year. I suggested that valuation was an issue at the time, but I certainly didn't grasp just how serious it was.

As for GT Solar, this maker of polysilicon and photovoltaic production equipment had its own stumble in 2008, just the day after its IPO. After LDK Solar (NYSE:LDK) announced that it had chosen a different supplier, the shares did briefly recover, but it's been tough sledding since then.

Granted, GT had one shockingly strong quarter, but it subsequently went splat. Now, the company has replaced its CEO. By some bizarre coincidence, the new chief exec also sits on the board of Verso Paper (NYSE:VRS), the only IPO to out-stink GT Solar in 2008. It's entirely possible that the fellow can turn things around at this shop. He inherits a $1 billion backlog and a clean balance sheet, so there are worse places to be.

The main problem is that new orders are slim, and customers are breaching contracts. Since the end of the quarter, "de-bookings" have exactly matched new orders of $16 million. Management also noted on the conference call that as much as 20% of the backlog is at risk, though it expects that most of its stretched customers will "substantially perform on their obligations." These dynamics are largely out of any one CEO's control, but it will be informative to see what steps the new management takes to secure its future as a solar supplier.