Just because Fool HQ was closed for business on Friday, that's no reason to leave Foolish solar investors in the dark. Hence, I bring you last week's key goings-on with a slight delay.

Energy Conversion Devices (NASDAQ:ENER) kicked things off Monday with its first-quarter earnings report. The company, which has been idling facilities in the face of a demand lull, had already prepared investors for the worst. Two analysts appear to believe that the market has priced ECD for the worst case, as well, and have since removed their sell/underweight ratings on the stock.

Also on Monday, Suntech Power (NYSE:STP) announced it was looking for a site for its first U.S. factory. The leading Chinese company said last year that its U.S. investment plans were contingent on clearer federal subsidies, which we got. Suntech has taken 2009 expansion off the table, but the company's clearly focused on the longer-term prospects of the U.S. solar market, which is starting to look pretty attractive compared to former darlings like Spain.

On Tuesday, some solar suppliers went splat. Q-Cells, the European solar cell heavyweight, also revealed a rough quarter. The company revised its revenue outlook for the third time and said it would exit its investment in thin-film start-up CSG Solar. The company's Solibro subsidiary will keep Q-Cells in the thin-film game, which is seeing more players hit the disabled list lately.

BrightSource Energy doesn't do thin film, but it's generating plenty of buzz anyway. The solar thermal player bumped up an existing 900-megawatt project pipeline with PG&E to 1.3 gigawatts, matching BrightSource's equally massive deal with Southern California Edison. This is some of the steamiest action in solar, period. It looks as though investors like Google (NASDAQ:GOOG) and Chevron (NYSE:CVX) are getting their money's worth here.

Speaking of deals, Yingli Green Energy (NYSE:YGE) rounded out the week with an impressive one of its own. The company sewed up an exclusive three-year supply deal with the solar arm of power player AES (NYSE:AES). The selection of Yingli over First Solar (NASDAQ:FSLR) shows that traditional crystalline PV suppliers remain competitive when it comes to utility-scale solar projects. It also speaks to Yingli's low-cost status within that group.