I also dont agree that the mining industry was doomed regardless.
It was planned by the tories that if they won the 1979 election(and it is documentd)that they would take on the miners and do whatever it took to beat them.They knew that if they beat the miners then the rest of the unions would would soon roll over,and Thatcher had a personal vendetta against them for bringing down the Heath govt.in which she was a minister.
Luckily for her they were led by a bloke with the intellect of an educationally sub normal gnat.He could have beaten her but he was way to stupid.
Meanwhile the farmers (who are always tories)carried on recieving huge subsidies from the taxpayer and of course almost every business in the country which employs more than a handful of people is now getting subsidies and we are importing very expensive foreign coal to fuel the coal fired power stations,The whole energy industry in this country is now owned by foriegners and they blackmail us constantly,so maybe it would have been better to chuck Scargill off a boat in the middle of the night and keep the mines open,with sensible management(rather than the lunatic mcgregor) and moderate unions.
The truth is Albitz is the mines were over-producing expensive, and growling expensive, subsidised coal that no one wanted in those quantities from many outdated pits. The majority of houses were not using coal anymore, nor were ships, factories, nor the railways that had ceased using that fuel 11 years before 1979.
King coal was dead, and the country only needed the coal for, as you rightly state, the coal fired power stations, which this country should have lost by now! So why keep an industry going that was out of date, highly expensive to run, not wanted, and dangerous to work in. Indeed on the last point I have heard and seen many ex-miners admit they never wanted their sons to work in such diabolical conditions.

So it makes sense to import the extra coal we need (I believe we do have a few mines still producing including open-cast ones), as our needs decline to zero with the closing (hopefully) of all coal fired power stations. 8-)