Tessera Solar North America Inc.’s parent company, NTR Plc announced Feb. 17 that it reached an agreement to sell off the 709-megawatt (MW) Imperial Valley Solar Project in California to AES Solar.

It’s the latest blow to Tessera Solar’s and Stirling Energy Systems’ plans to build large-scale solar projects in California and elsewhere in the U.S.

“AES Solar intends to move the project forward and is committed to working with San Diego Gas & Electric to fulfill its obligations under the power purchase agreement,” said the company in a press release announcing the sale. NTR said Tessera and Stirling Energy Systems have, for now, halted deployment of the SunCatchers for the Imperial project. “Ensuring that the project will deliver its full potential of solar power in the near-term,” The company said.

Regarding the sale, Tessera spokesperson Janette Coates said, “Tessera Solar is assessing the recent transactions and their impacts on the business.” She added that “Stirling Energy Systems is engaged in a confidential process of seeking a strategic investor to continue the commercial deployment of the SunCatcher technology.”

“I am very pleased that the Imperial Valley Solar Project will be brought to the next phase of development by AES Solar,” NTR CEO Jim Barry said in the release. “They have a significant pedigree in developing solar projects and through their efforts, we are confident that the value created by Tessera Solar in this project will be enhanced for NTR shareholders over time.”

Tessera has faced other stumbling blocks lately.

In early January 2011, Tessera announced that it sold the Calico Solar Project to K Road Power Holdings, LLC., after losing a power-purchase agreement with Southern Edison California. The Calico plant was a proposed 850-MW solar farm that, like the Imperial Valley Solar Project, would have used Tessera’s SunCatcher technology to generate electricity.

Unlike most other solar technologies, Tessera’s SunCatchers produce electricity by focusing solar heat on Stirling engines. The company has thus far had problems bringing them to fruition and attracting financing for the projects. Tessera said it has demonstrated the technology at its Maricopa Solar installation.

“Maricopa Solar continues commercial operations and the delivery of solar power to the grid,” Coates said. She added that the plant has demonstrated the viability of the SunCatcher technology in a commercial setting. “[It] has proven to be a valuable source of data as we continue to commercialize the SunCatcher.”

AES Solar, a partnership of AES Corp. and Riverstone Holdings, is working to finance and develop utility-scale solar power project across the world. The company is based in the U.S. and has developed solar projects in France, Italy and Spain.

AES did not respond to requests for comment. And the companies did not disclose the purchase price for commercial reasons, NTR said.

Image courtesy of Stirling Energy Systems