I'm not so sure you are free of the Grid because the prices you pay for the coal are tied by the whole economics of substitution; it is not, after all, your coal mine in the back yard which you have kept secret from everyone else. When the Grid gets tight, I'm thinking you will find that coal hard to find.

cfm in Gray, ME

Even in Pennsylvania, people willing to sell good anthracite coal to new customers were already hard to find. We looked into a variety of coal, wood, corn, wood pellet and even rice coal stoves, and found that wood and wood pellets were really the only fuel we could readily buy. We knew people that used coal, but none of the suppliers were interested in new customers.