The British are coming…to help build solar power plants in the US.

Barclays Capital will partner with K Road Power for a “substantial commitment to fund” continued development, construction and operation of several major solar installations across the country, Barclays Natural Resource Investments (BNRI) announced on Tuesday.

“K Road, with its experienced leadership team and high quality projects, has quickly established itself as one of the preeminent renewable energy developers in the US,” BNRI Managing Director David Ellis said in a statement.

K Road’s is currently developing some of the country’s largest solar projects, including an 850 MW plant in San Bernardino Country, California and a 350 MW solar project just north of Las Vegas. The company now manages 11 solar projects in the US’s southwest, which add a total of 2300 MW to the California and Nevada grids.

Although solar power account for only a fraction of the US electrical generation capacity, it has in some cases overtaken wind as the renewable generation source of choice. The capacity to build solar closer to cities, with shorter transmission lines, is part of the appeal. Solar also has fewer moving parts, making it easier to construct and manage than large turbines.

Grid connected solar photovoltaic (PV) installations grew 66% from Q1 2010 to Q2 2010, according to the Solar Energy Industries Association. Roughly 2.85 GW of solar capacity is currently installed in the US, a first quarter 2011 report from the Energy Information Administration says, with prices dropping 15% quarter over quarter.

With current solar tax credits set to expire at the end of 2012, investment in the sector relies to some extent on the rapidly declining costs of solar PV panels and the promise that the industry will very soon reach grid parity.

At the recent REFF Wall Street, investors from major banks discussed the prospects of the solar PV market. Read the full story: Scaling And Financing Solar PV: Notes From REFF.