What are the economics for the use of Natural Gas....?
Can a plant using the high pressure on water and coal be switched to natural gas....
Assuming a BTU doesn't care where it comes form....loosely speaking.?
Right now, pretty good. But historically, Nat Gas prices swing wildly while coal prices are relatively more stable.
Can a plant using the high pressure on water and coal be switched to natural gas....
If you are asking if a coal fired plant can be converted to a gas-fired plant the answer is yes. Requires new burners and associated systems, but it can and has been done.
But Natural Gas is best used in combined cycle plants (gas turbine-generator followed by a Heat Recovery Steam Generator and a steam turbine) which reach far higher BTU efficiency levels. That is far different than the typical coal-fired boiler arrangement. So economically, it depends on the price of the fuel.
But as far as grid operations, load balance and response time there are other considerations that must be factored in. The grid can not be all one thing or all the other. Different fuels and plants offer their own technical and economic advantages.