Alcoa tests aluminum-based solar power system

* Alcoa working with National Renewable Energy Lab

* Project partially funded by a $2.1 mln DOE grant

* Test results expected by second quarter

NEW YORK, March 18 (Reuters) - Alcoa Inc  said on Thursday it is testing solar technology that uses aluminum instead of glass mirrors to generate electricity by concentrating sunlight.

The aluminum producer is working jointly with the U.S. Department of Energy's National Renewable Energy Lab (NREL), with the goal of making concentrating solar power technology (CSP) competitive in the United States by lowering its cost to generate energy, it said.

NREL and Alcoa recently installed an Alcoa-designed Concentrating Solar Power parabolic trough at NREL's test facility in Golden, Colorado. Tests will measure the 20-foot (6-meter) by 46-foot (14-meter) collector's efficiency to generate energy and evaluate its structural performance.

Currently, commercial concentrating solar power systems use glass mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat.

Instead of glass, the new Alcoa system uses highly-reflective aluminum mirrors, which are more durable and environmentally friendly, the company said.

Most solar energy systems use photovoltaic technology, in which sunlight is turned into electricity by solar panels, but  CSP, or thermal solar technology, is expected to get a boost   with several installations slated to be built in coming years.

The Alcoa project is being partially funded by a $2.1 million DOE grant. Test results are expected by the second quarter this year, after which the system will enter the next level of large-scale testing, the company said.

(Reporting by Steve James;Editing by Steve Orlofsky)