So they did a study called “Biomass Supply and Carbon Accounting for Southeastern Forests”
And they came up numbers for a bunch of technologies and broke out the CO2 emissions for transport and for power production using lbs/MMBtu.
CHP power plants are most efficient. “CHP involves the use of a steam turbine which is designed not only to drive a generator, but also to produce steam or hot water.”
So the top choice would be Coal CHP where the waste water is used in a central district heat type situation.
Next choice would be Natural Gas. Then New coal power plants.
The absolute worst choice is wood pellets because transporting those pellets generates a lo of CO2.
Which is what they are shipping to the UK (and many other places) to burn in DRAX.