On Monday, Yingli Green Energy (NYSE: YGE) caught a downgrade from Macquarie analysts, after the firm started making polysilicon in-house. This was previously the only missing link in Yingli's vertically integrated manufacturing process, which the company filled by acquiring start-up Fine Silicon in early 2009.

Yingli expects to start commercial production sometime in the first half of this year. Unfortunately, ramping up this sort of operation can be tricky. Any bumps in the road could pressure Yingli's cost structure relative to competitors like Trina Solar (NYSE: TSL), which made the critical decision not to go down this road several years ago.

Also on Monday, solar encapsulant specialist STR Holdings (NYSE: STRI) boosted its guidance for this key business segment "due to recent strength in the global solar market." I haven't given this company more than a glance, but it's enjoyed stellar post-IPO performance, leaving firms like GT Solar in the dust. Let me know whether you'd like to see an in-depth feature on this one, and I'd be happy to oblige.

On Wednesday, JA Solar (Nasdaq: JASO) lifted its shipment guidance for the first quarter, representing about a 20% boost to the midpoint of its former range. Its first-quarter strength was never really in question, but it's shaped up to be quite a stunner. Another midweek surprise came from SatCon Technology, which landed a large inverter order from China's GCL Solar.

Less sunny news came from Signet Solar, which failed to win Department of Energy funding to build an amorphous silicon PV plant in New Mexico. Signet is one of Applied Materials' (Nasdaq: AMAT) more high-profile SunFab customers. Another one recently went bankrupt. This approach to solar module production is really not faring well in the hypercompetitive race to grid parity, and Applied is reportedly reconsidering its support for the SunFab unit.

We've noted Ontario's support for solar through a generous feed-in tariff structure, which has opened the door for firms like Canadian Solar (Nasdaq: CSIQ) and MEMC Electronic Materials (NYSE: WFR) subsidiary SunEdison to make a big renewable-power push in the province. The downside of that support? According to the Globe and Mail, Ontario's power prices are headed 25% higher by the end of 2011.

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. The Motley Fool has a disclosure policy.