A 30-megawatt solar farm in New Mexico, will be built by First Solar (FSLR) which has entered into a contract with the Tri-State Generation and Transmission Authority.

The New Mexico contract is worth around $98 million to $113 million and will move this part of First Solar’s business up to 200 megawatts by 2010. The California Public Utilities Commission will also argument for and against a project for First Solar to build 250 megawatts for Southern California Edison on March 25.

Companies such as Ausra, eSolar and Optisolar have landed the rights to build utility-scale projects. All three, though, have ran out of the money and credit necessary to go through with their plans. So they have sold the rights. First Solar, for instance, is taking over Optisolar’s role in building a 550-megawatt plant for PG&E (PCG).

Meanwhile, the Rancho California water district announced the completion of a 1.1 megawatt solar system at its plant in Murrieta. SunPower (SPWRA) built the facility and sold the power back to the water district under a contract that could save the utility 6.8 million over 20 years.

A similar large-scale solar project with a water agency is expected to be announced soon in San Francisco, according to sources.

Roughly 19 percent of the power in California is consumed in processing and transferring water so for water agencies, it’s a good deal. Water agencies also have spare real estate on the roofs of their processing plants that could be put to work. Las Vegas’ municipal water authority has installed solar panels on many facilities.

Although consumers and homeowners continue to account for a significant portion of U.S. solar sales, solar manufacturers are increasingly moving toward utility scale solar parks and large-scale projects. Utilities can get access to capital to build these things, and many are under pressure to meet mandates for renewable power. In California, utilities are supposed to get 20 percent of their power from renewable sources, not including large hydroelectric dams, by 2012.

Back in 2006 when Google (GOOG) announced it had erected a 1.6-megawatt system, it was the largest private solar installation in the U.S. Since then, Applied Materials (AMAT), several military bases and other customers have installed much larger systems.

Image by Rail Life on flickr under the Creative Commons license.