Today’s solar power rundown will be short and sweet, with a focus on: collective solar installations in Colorado and beyond; an aluminum giant’s foray into solar power; and a decent-size solar power project in California’s central valley.

U.S. Sen. Mark Udall (D-Colo) announced yesterday that he will introduce a bill to extend the 30-percent residential solar tax credit to “community-based,” collective solar installations, via BusinessWeek. Dubbed the Solar Uniting Neighborhoods Act, Udall’s proposal would all homeowners to receive federal tax credits for solar panels installed elsewhere. Renters and people with shady roofs unite! See yesterday’s Rundown for more on solar energy gardens in Colorado.

Chinese solar-panel maker Trina Solar Ltd. (NYSE:TSL) says it will offer 8 million American depositary receipt (ADR) shares, via Forbes. The company plans to use the proceeds for R&D and to expand manufacturing facilities for the production of solar cells and solar panels.

Another story comes out of Roseville, Calif.: Solar Power, Inc. announced yesterday they won a contract with Baldwin Park Unified School District to install a number of solar installations across its school district, via a press release on MarketWatch. How big are we talking? Eight projects that together comprise a solar system size of 2.24 megawatts.

Aluminum-making giant Alcoa (NYSE:AA) is piling into the solar energy sector, according to a press release. The company announced today it is jointly testing an “advanced solar technology” with the U.S. Dept. of Energy’s Renewable Energy Lab (NREL). The aim? (1) Simply the design of parabolic reflectors, and — related — (2) drive down manufacturing costs to make concentrating solar power (CSP) technology more competitive. They’ll face stiff competition, as Google has in the paced placed bets on making solar thermal technologies cheaper and more competitive, too. And, as Todd Woody of Green Inc. points out, a solar + aluminum could be an interesting, if not ironic, mash-up, as the metal requires an enormous amount of energy to manufacture.

In California solar installation news, SunPower will build at 1-megawatt solar energy system for Yolo County, via PRNewswire. The system will be sited at the Yolo County Justice Center in Woodland, Calif., and will be made possible in part by energy conservation bonds available through the American Recovery and Reinvestment Act (ARRA). It goes without saying that Yolo County — which incorporates Davis, West Sacramento, Winters and Woodland — gets a boatload of sunshine each year.

Related, a large California solar installation project is making progress, according to NYTimes.com. The planning stage has been something of a roller coaster ride for many observers. Like any major engineering project, large-scale installations face a rigorous review process, which typically involves environmental impact assessments and periods for public comment. For more, see these GetSolar tidbits:

That’s all, folks. Post your comments and suggestions below — and we’ll see you back here tomorrow!