True. So what. There is a full spectrum of "costs of production" over many different oil wells....some of them will shut down, some won't.
"With coal mines heavily mechanized (if not quite automated although that's probably not that far off), coal has to sell at a sufficiently high price to pay for the electricity and capital costs ~ and the machinery requires a CREW, not just a miner with a pick and shovel."
Again, so what. "Capital costs" have already been invested. And the cost of the "crew" is much smaller.
"It's easy to see virtually every coal mine in America falling out of use as the price of coal drops like a rock.
See above point about different mines having different costs of production. Some will shut down, some won't.
"These price collapses will occur BEFORE there are sufficient numbers of cold fusion units to replace their energy output.
And why would that happen?? Demand will still be there for gasoline and coal to drive automobiles and power generating plants, which demand will only disappear as fast as those units are replaced by the fusion units, and no faster.
It's happened before. It'll happen again.
You realize this nickel to copper conversion device has the power to DEFLATE money like nobody's business. There will be no polite retreat from coal and oil and natural gas to the new system.
In the aggregate the "off switches" will follow a quantum curve ~ not an analog curve. On Monday wells are pumping. On Tuesday all the oil pumped will not recover the costs of doing so and they'll be turned off.
The guys with some cash are not going to be subsidizing your continued use of coal or oil.