There are also wood gasifiers. Old technology they used post-WW2 because of oil shortage.

All moot though because the eco nutters are going to block it. Wood pellet stoves used to be a big hype a few years back around here. Then the Green retards found a way to fight it, "muh bound CO2" and "muh fine particle dust".

If it doesn't involve rare materials from 3rd world stripmines, hard to recycle toxic waste and dependency on foreign nations, it's got no future.