Even if cold fusion worked. It would be so cheap that the government may not allow it to be built for running everyone else out of business in the energy market.
I read where there have been 10-15 patents to improve gas mileage ever since the 1920's, but the patents were all bought up by the oil companies back then so never brought to market.
I also saw where a Japanese man invented a ultra sound washing machine. It looked like an aquarium. You put the dirty clothes in there and the ultra sound machine knocked the dirt out of the clothes without detergent. This was on the Discovery channel or something like that. The Japanese detergent companies bought up the patent and it never came to market. It used about 1/6th the electricity as a traditional washer. He also developed a microwave dryer, but metal snaps and buttons didn't work in it. It used less power than a traditional dryer. Neither had hardly any moving parts.
No telling what has been invented and patents bought by a competition that would be going out of business.
I worked in the natural gas industry for 40 years. There has been disinformation put out by the oil companies against wind and solar. The "greenies" have also put out disinformation about the oil and gas industry too. That is one reason why I take the middle ground.
ALL energy sources should be developed to the max. If our country was awash in plentiful cheap energy, it would attract new industry and bring a lot back home.
Excessive enviromental regulations, not allowing pipelines, etc have caused prices to rise. Wars cause prices to rise. Florida has consistantly voted against offshore windmills because of the ocean view. The feds may FORCE them to put some in. Massachusetts off Marthas Vinyard several years ago voted against offshore windmills, but the Feds may make them put the up. Anyway when this vote came in, they voted instead to put in a fuel oil generator using imported oil.