“…and that that natural gas powerplant efficiency is about 40%[3].“ The next line in your reference points out that combined cycle plats are >60% efficient whi

“…and that that natural gas powerplant efficiency is about 40%[3].“ The next line in your reference points out that combined cycle plats are >60% efficient which are pretty much all gas plants. 60% of the energy in gas is turned into electricity.