LOS ANGELES, Dec 11 (Reuters) - Royal Dutch Shell RDSa.L on Tuesday became the latest oil company to invest in technology that uses heat from the sun to tap hard-to-reach supplies of crude in aging wells.

The oil giant, along with three venture capital firms, is pouring $26 million into California startup GlassPoint Solar Inc., the company said in a statement.

GlassPoint uses the sun to heat water and create steam for so-called enhanced oil recovery. The steam improves the flow of heavy oil from depleted fields. Most EOR systems burn natural gas to create steam, but GlassPoint says its technology is cheaper.

GlassPoint operates a commercial solar EOR project at a Berry Petroleum BRY.N oilfield in McKittrick, California. It is also building a trial project in Oman with Petroleum Development Oman, a joint venture between the government of Oman, Shell, France's Total TOTF.PA and Portugal's Partex.

The company plans to use the new funds to expand in the Middle East, Chief Executive Rod MacGregor said in an interview, calling the region "a perfect storm for us... you have heavy oil, you have a shortage of gas and you have abundant sunshine," MacGregor said.

Shell invested in GlassPoint through its Shell Technology Ventures arm. Other investors in the company's Series B financing round included RockPort Capital, Nth Power and Chrysalix Energy Venture Capital.

Chevron CVX.N is also using solar EOR in partnership with solar thermal company BrightSource Energy at an oilfield in Coalinga, California.

(Reporting By Nichola Groom; editing by Andrew Hay)

((nichola.groom@thomsonreuters.com)(213-955-6755)(Reuters Messaging: nichola.groom.thomsonreuters.com@reuters.net))

Keywords: GLASSPOINT SHELL/