It may be that coal at $14 dollars is so cheap, and such a small part of the total cost of electricity, that it doesn't matter. Multiplying the price by 2, 3, or 4 may not be a big issue.

This is a quantitative question, so it's easy enough to get a rough answer by doing a little simple math. The answer boils down to "unlikely to be a problem".

Electricity in the US is roughly $0.10/kWh, and US coal generates about 2,000kWh/ton. Multiplying those tells us that the retail cost of electricity is $200 per ton of coal consumed, so a minemouth cost of $10/ton for coal represents only 5% of the overall retail price.

If the minemouth cost of coal rose to $30/ton, the retail cost of coal-fired electricity would increase only 10%, but economically-recoverable coal reserve would increase six times.

Based on this report, any reasonable discussion of ultimately-recoverable US coal reserves should use a figure of somewhere around 60bst. The headline figure of 10bst is useful for economic planning in the coal industry, but is not a reasonable estimate of long-term coal availability.

The bigger issue may be the availability of diesel for its entire role in the supply chain.

Most likely not.

Rail transportation is about 440 ton-miles/gal, and low-sulfur coal in the US travels roughly 1,000 miles before being used. Dividing these tells us that transporting US coal requires roughly 2.3 gal/ton.

Accordingly, each $100/bbl increase in the cost of oil will increase the cost of transporting a ton of coal by $100/bbl * 1bbl/42 gal * 2.3gal/ton = $5.50/ton, or about 3% of the retail price.

Coal transportation is much less sensitive to the price of oil than many other areas (particularly air and personal-vehicle travel), and can be converted in a relatively straightforward manner to use electricity instead of diesel, meaning that reduced oil supplies are highly unlikely to have a significant direct impact on the ability of the US to transport coal.

Gail,
It's easy to get carried away with the thesis that since oil is presently used for every aspect of industrial production, as we start to run out of oil, all industry will stop.
In the case of coal mining, transport, burning in power plants and distribution of electricity oil use is very small and can be easily replaced. Probably the largest use presently is for rail transport of coal.
All rail transport uses less than 1% of oil, and this can be replaced by electric trail, gas turbine trains or direct injection of coal in existing(modified) diesel engines. Before 1930, all coal was moved by coal-burning steam engines, but it seems simpler to use existing diesels with coal-powder/water fuels. This report is a good up to date summary of direct injection of coal in diesel engines.
http://www.ccsd.biz/publications/files/TA/TA%2074%20Efficient%20use%20of...