Xcel Energy is proposing to develop a utility-scale solar-power plant that would be among the first of its kind in the nation.
The 200-megawatt generator would create renewable power with no emissions, helping Xcel comply with state guidelines to increase alternative energy and decrease greenhouse gases.
The proposal, included in a resource plan filed by Xcel on Thursday with Colorado regulators, drew praise from backers of the technology known as solar thermal or concentrating solar power.
“Of course we’re thrilled that they’re moving toward a truly carbon- free technology,” said Leslie Glustrom, a solar-thermal advocate and critic of Xcel’s coal-fired generation. “We have a half-dozen developers champing at the bit to build these projects.”
Xcel officials said the timing, location and cost of the plant aren’t yet known.
Solar-thermal analysts have said a plant of the size proposed by Xcel could run about $600 million and cover 1,000 acres of land with solar collectors. It could supply power to about 80,000 households.
A possible location could be the San Luis Valley near Alamosa, rated as having Colorado’s best solar exposure.
Unlike conventional solar photovoltaic panels that convert sunlight directly to electricity, concentrating solar power uses large mirrors to focus sunlight on vessels containing water or other fluids. The heated fluids produce steam to spin turbine generators, similar to the way coal- fired power plants use steam to make electricity.
Analysts say solar thermal is less expensive, and better suited for large-scale power production, than conventional solar-electric panels.
The technology also is considered more useful than intermittent wind power because the collected solar heat can be stored for several hours, allowing power to be generated after the sun goes down.
In an interview Thursday, Xcel chief executive Dick Kelly said the utility is confident in solar-thermal technology, even though costs are higher than power generated from coal or natural gas.
He said Xcel believes costs will go down as the technology becomes more prevalent. Xcel may seek other utility partners for the project.
Xcel officials said the resource plan proposes initially a smaller, 25-megawatt plant by 2011 that could employ both solar-thermal and photovoltaic collectors.
The larger plant of up to 200 megawatts would be developed later, before 2016.
A handful of solar-thermal developers said they have been eyeing the San Luis Valley for solar generating plants. Xcel and SunEdison already have a 8.2-megawatt photovoltaic facility there.
“What the industry seems to have discovered is that larger plants are more economical,” said Mark Mehos, a solar-thermal researcher at the Golden-based National Renewable Energy Laboratory.
Mehos has described the technology as “very promising” in the movement to reduce fossil-fuel power generation.
Steve Raabe: 303-954-1948 or sraabe@denverpost.com
This story has been corrected in this online archive. Because of a reporting error, it was incorrectly stated the capacity of a solar-power plant in the San Luis Valley being developed by Xcel Energy and SunEdison. The correct capacity is 8.2 megawatts.
