Lest you believe Solyndra is an isolated case of a multi-billion-dollar, taxpayer-subsidized energy company going belly up, think again. Beacon Power has filed for bankruptcy. USA Today, with the scoop:

WASHINGTON — A Massachusetts energy-storage company that received a $43 million Department of Energy loan guarantee has become the second green tech company backed by U.S. government financing to file for bankruptcy court protection in two months.

News of Beacon, which makes flywheels that manage energy moving through a power grid, follows the White House announcement last week that it was enlisting Herbert Allison, a former Treasury Department official who has worked in Democratic and Republican administrations, to audit the entire loan program.

Might as well start a list of the DOE’s picks that have gone belly up. Possibly on the list soon: Ener1. From Politico:

An advanced battery manufacturer that was awarded millions in federal stimulus dollars is now in financial hot water and is being closely monitored by the Energy Department.

New York-based Ener1 received a $118.5 million grant to expand its manufacturing operations in Indianapolis, Ind., run by a subsidiary EnerDel, which received a visit from Vice President Joe Biden earlier this year.

But NASDAQ pulled the firm from trading Friday for failing to file its most recent quarterly report on time. Ener1 also let go of its chairman, Charles Gassenheimer, late last month.

Now DOE says it’s watching the company.

“The department is closely monitoring the status of the company,” DOE spokesman Damien LaVera said in an email Monday.

“So far $55 million of the grant has been paid out to EnerDel,” he added. “Any additional funds received from the government would need to be matched dollar for dollar with their own investment.”