[ExI] Coal power through syngas

[Keith Henson]

If you just burn a tonne of coal for power, you get around 2.2 MWh
~40% efficient.

If you gasify a tonne of coal using 4 MWh of off-peak renewable power,
you get about 12.5 MWh of syngas, which you can burn to get 6 MWh of
power.  Thus, you can get about 3 times as much energy from a tonne of
coal by gasifying it first as you get from burning it.  Of course, you
need to put in 4 MWh of renewable energy to do that.  But it still
beats burning it, and if you want, you can sort out at least half the
CO2, perhaps all of it, for sequestration, leaving cheap, more or less
pure hydrogen.

Keith