China’s plans to build 2,000 megawatts of solar thermal power using technology from a California company, eSolar, will also include the construction of biomass power plants to generate electricity when the sun sets.
The solar and biomass plants will share turbines and other infrastructure, reducing the projects’ cost and allowing around-the-clock electricity production, according to Bill Gross, eSolar’s chairman.
“That supercharges the economics of solar,” said Mr. Gross in a telephone interview, noting that the addition of biomass generation will allow power plants to operate at 90 percent of capacity.
Under terms of the deal announced Saturday in Beijing, eSolar will license its “power tower” technology to Penglai Electric, which will manage the construction of the power plants over the next decade.
Another Chinese company, the China Shaanxi Yulin Huayang New Energy Company, will own and operate the first projects to be built in the 66-square-mile Yulin Energy Park in northern China.
A local shrub grown in the surrounding region to fight desertification, called the sand willow, will supply fuel for the biomass power plants, according to Penglai Electric.
“It’s an economical use of a resource that’s already in place,” said Nathaniel Bullard, a solar analyst with Bloomberg New Energy Finance, a research and consulting firm. “That’s a very savvy move, rather than attach an energy storage system to the solar project.”
(A 107-megawatt project in California being developed by a Portuguese developer plans to use a similar biomass hybrid solar design.)
As The Times’ Keith Bradsher pointed out in his story, one issue with solar power plants in China is the large amount of land they require.
Eric Wang, a spokesman for Penglai Electric, wrote in an e-mail message that the relatively small footprint of an eSolar plant compared with other solar technologies proved attractive to the Chinese developer of the $5 billion project.
ESolar’s power plants deploy fields of mirrors called heliostats to focus the sun’s rays on a water-filled boiler that on a tower. The heat vaporizes the water and the resulting high-pressure steam is piped to a power block, where it drives an electricity-generating turbine.
The company uses a software control system and imaging technology to control 176,000 small mirrors that form arrays at its standard 46-megawatt power plant. The software positions the mirrors to create a virtual parabola to focus the sun on the receiver tower. That allows eSolar to make the mirrors cheaply and pack them close together to reduce the size of the power plant.
Mr. Gross noted that in California unskilled workers need 15 minutes training to learn how to install the solar fields. “In China, they wanted to use untrained labor as well,” he said.