By Julian Hattem - 04/29/13 09:44 PM EDT
Among the signers of the letter are Chairman Fred Upton (R-Mich.), Vice Chairwoman Marsha Blackburn (R-Tenn.) and former Chairman Joe Barton (R-Texas).
Republican legislators have often accused the program of propagating "crony capitalism," as Mitt Romney claimed in a visit to Solyndra's shuttered offices last year.
The Energy Department's website claims that the loans have created approximately 60,000 jobs, though that number includes construction positions such as the 3,000 brought by Solyndra.
The troubled electric automaker Fisker, which has received $192 million in federal loans, has been the most recent example for the program's opponents. The company is on the verge of bankruptcy and has laid off the vast majority of its workers in its struggle to stay solvent.
Last week, the government seized $21 million from the car company, and its founder was subject to a barrage of criticism in a hearing before a subcommittee of the House Oversight and Government Reform Committee.