[broadgage]

One of the original reasons for building the national grid was to facilitate the burning of coal in large modern, high efficiency power stations situated in the coal fields.

It was indeed cheaper to transmit electricity by high voltage grid lines, than to transport coal to power stations nearer the load.
Electrical losses were said to be 1%.
Coal losses in extra handling, and the coal burnt by steam locomotives to haul the coal were said to be 2%.
A well built grid line was less vulnerable to bad weather than a railway.
OTOH, a railway built primarily to transport coal was also useful for other traffic.

All a bit academic these days as coal is much less used.