Well that and then the deeper you drill, the more you will need to pump. There are significant complications. On paper I agree - pragmatically it still seems far away when we have great options already available: I mean alternatively we could use the power of the Sun (technology we have already developed). We could also use uranium and plutonium to power long lived electricity. Convert that electricity to heat via heat pumps (already available tech).

All for improving drilling tech -- maybe let O&G bare most of the cost of research though if we need to compete for research dollars.