Wood pellets used in the largest UK power plant (Draxx) are not a bi-product of logging.
This power plant consumes more than 7Million tonnes of wooden pellets per year. Most of that fuel comes form North America:
4.5 M t from USA
1.5 M t from Canada
Sorry, the wood pellets are a by product of sawmills shavings.
The shavings from sawmills are converted to pellets.