On Monday, Greek thin-film PV player HelioSphera unveiled a plan to build a $500 million manufacturing plant in Philadelphia. That would be one of the larger investments we've seen in domestic solar capacity, with shops like Yingli Green Energy (NYSE:YGE) taking baby steps in this regard.

Also on Monday, the website PV-Tech reported that SunPower (NASDAQ:SPWRA) risks losing its long-held No. 1 spot in California market share. Japan's Sharp has pulled ahead on a year-to-date basis, with 17% share to SunPower's 16%. Suntech Power (NYSE:STP) is also making strides here.

Speaking of Suntech, the Chinese leader signed a 17-megawatt supply agreement with a Toronto-based installer. Suntech's not the only company looking to cash in on Ontario's feed-in tariff. Canadian Solar (NASDAQ:CSIQ) announced plans to build a 200-megawatt module factory in the province, which has written significant local content requirements into its subsidy program.

Trina Solar trotted out an announcement about recent supply deals in China, but this merely underlined how miniscule this nascent market remains. Eight megawatts of modules are really nothing to get excited about.

Even less exciting was Energy Conversion Devices' (NASDAQ:ENER) announcement of yet another restructuring plan. The company is cutting 20% of its workforce in order to "better align operating expenses with near-term revenue expectations." Expectations for this company are understandably hitting new lows by the day.

On a sunnier note, LDK Solar (NYSE:LDK) and Q-Cells managed to patch things up this week, dropping legal action against one another regarding a disputed supply contract. The six-gigawatt contract carries on, but with deliveries more back-weighted than originally envisioned.

Rounding out the week, Solarfun Power (NASDAQ:SOLF) signed an agreement to build a 100-megawatt solar power plant in western China. While Trina's announcement points to the demand reality on the ground today, this proposed plant by Solarfun, and the many other preliminary agreements just like it, do suggest a possibly robust future market.

Fool contributor Toby Shute doesn't have a position in any company mentioned. Check out his CAPS profile or follow his articles using Twitter or RSS. Suntech Power is a Rule Breakers recommendation. The Motley Fool has a disclosure policy.