Natural gas is rather clean and it can be stack scrubber processed to make it even cleaner. The USA has reserves to last 1000+ years. The plant I visited in Antioch CA could be brought online in 45 minutes.
21 megawatts and change output. But every transmission line, distribution line and service line will have to be trebled or quadrupled in current capacity. A 120 Mw transformer 12 Kv to 750 Kv costs about 12 million dollars. To have a nationwide intertie is a trillion(s) dollars effort, including sub distribution. Realize the time and money in this. It takes about a month to construct the largest transmission transformers. The USA does not product the faintest shadow of that kind of manufacturing capacity. And it all has to be paid for -- every last tower strut.
