That's really an excellent point! Thanks. Using renewables or nuclear power to extract fossil fuels amounts to something almost like indirect energy conversion

That's really an excellent point! Thanks. Using renewables or nuclear power to extract fossil fuels amounts to something almost like indirect energy conversion/storage. It can also work between fossil sources. I've heard the tar sands described as a massive indirect gas liquefaction plant -- it's economical because direct GTL is less efficient than gas -> steam -> bitumen -> liquids.