Energy Secretary Steven Chu stood firmly behind his department’s efforts to address volatile gas prices and invest in clean-energy projects Tuesday amid aggressive attacks from House Republicans.

Chu, during a tense House Oversight and Government Reform Committee hearing, defended the Energy Department’s embattled loan program and gave the agency high marks for working to develop a long-term plan to protect consumers from soaring pump prices.

At one point, committee Chairman Darrell Issa (R-Calif.) asked Chu whether he’d give his efforts to control gas prices an “A-,” the same grade he gave to the department’s work on the loan program.

“The tools we have at our disposal are limited, but I would say I would give myself a little higher in that since I became secretary of Energy, I’ve been doing everything I can to get long-term solutions,” Chu said.