What you say is true, but water simply contains no potential energy. The humidity of induction air has a bearing on the energy produced. Harrier jets add water during vertical takeoff, but water also destroys engines, due not only to corrosion, but to steam case hardening piston rings, loosening contact pressure onto the bore and even causing them to crack. The Harrier never injects water during flight. ALL of the benefits of adding water have been surpassed by modern injection systems that run at up to 2,200 bar. I could easily adjust my car to return 100'mpg, but both the acceleration and top speed would decrease and their would be flat spots during acceleration. Far more importantly, exhaust gas temperature would exceed limits, burning exhaust valves and causing complete engine failure within less than 1,000 miles. No one would ever market such a car. Few people realize that at 'Full Ahead' the rpm on the engines of large ships are set my the speed governors keeping exhaust gas temperatures at the optimum. Formally, engineers read gauges and adjusted 4 times an hour, but today it is fully computerized and rpm can adjust every 5 seconds. Many of these engines that run between 200 and 425 rpm have completed tens of millions of miles over 30 plus years. Take a look at a ships engines control room at 22:40 on this video.
Ummmm... Do you think these are cheap? Why would utility companies who are burning cheap coal bother to invest billions in alternative energy? Because the care about the environment? HA HA HA, right! Or maybe because they know something about their fuel sources...
I don't know about that but I do know there is a possibility that the gas shortage was really a ploy by oil and gas companies to hoard all of the fuel then sell it back to us at jacked up prices. Oh and that there was a race car driver who's name was Dick Trickle.