A one-megawatt flywheel system is arrayed at Beacon Power Corp., in Tyngsboro, Mass., July 30, 2009.

The Obama Administration is welcoming news that federal regulators have approved the sale of Beacon Power, one of several alternative energy companies that struggled financially after being among the first selected to receive loan money from the Energy Department.

The sale of Beacon to Houston-based Rockland Capital means the government will be back in position to recover a significant portion of the $39 million in federal money the company spent before filing for bankruptcy in October.

"Rockland Capital's purchase of Beacon Power … means that the Department stands to recover more than 70 percent of our investment, and reaffirms that this is a valuable project with important technology," said Damien LaVera, an Energy Department spokesman, in a statement to ABC News.

"Rockland's commitment to this project highlights the need to continue to make investments in innovative, commercially viable projects that can help America compete for the clean energy jobs of tomorrow," LaVera said.

Before Beacon went bankrupt, it had built a flywheel plant in New York that uses unique technology to help make the flow of power on the electric grid more efficient. Under its new ownership, that plant will continue to operate, and plans for a second plant in Pennsylvania will get underway.

The sale was announced a month ago, but needed approval from the Federal Energy Regulatory Commission, which came late last week.

"We're pleased to make it possible for this company and its talented team to continue to innovate and grow, and to provide a runway to facilitate a path to commercial success," said Scott Harlan, Managing Partner for Rockland Capital.