Yes, Dub-dub - I'd agree with your dating: somewhere between 1800 and 1820, I think. And at that time, rural areas were still very reliant on wood and charcoal for their fuel (or peat, in Northern parts - this wouldn't apply to Hardy country, though.)

Coal was in common use in the towns, from about the 1770s, as wood was becoming increasingly scarce ( therefore expensive, of course.) The towns were well served by the canal system by the early 1800s - the first large canal had been from a coal mine at Worsley to Manchester (about twelve miles, probably), and it brought the price of coal down to a third of its pre-canal price.

From this you can work out that transport costs, pre-canal and pre-railway, were high. This is why coal wasn't used very much in the rural areas, except where the canal ran through the countryside.
It may also have been a factor in making wood a less viable fuel option in towns.