Normally, the UK pays 50£ per MWhr. But for biofuel electricity they pay 105£ per MWhr. This makes it worthwhile to buy biomass pellets on the world market and North Carolina is happy to oblige. The CO2 emissions of cutting trees down in North Carolina, converting to biomass pellets, shipping them to the UK and burning them there is greater than if they had used domestic coal. The price for biomass pellet burning electricity his higher than wind, higher than solar.
It's all just one more example in a long line that shows that government doesn't know how to calculate a price and should be in the business of price setting as little as possible.
HT: Clayton Cramer