The 60% was specifically about a good, big GE combined cycle natural gas plant. I was under the impression that for a purely steam powered generator, such as y

The 60% was specifically about a good, big GE combined cycle natural gas plant. I was under the impression that for a purely steam powered generator, such as you have in a coal or nuclear plant, significantly less than 60% of the heat turns into electricity. I thought he was also saying that an internal combustion engine burning natural gas is about 20% efficient, with the implication that if you are absolutely determined to power a vehicle with natural gas, burning the gas in a big turbine and using it to charge batteries is going to be significantly more energy efficient than burning the natural gas directly in the vehicle.