There would definitely be no energy crisis in 1979. OPEC would drive the price of oil low enough to get more business.
Why would they do that? You can profit by maximizing profit margins or maximizing sales. As an inelastic resource, the best way to profit is to maximize margins.
In terms of weight, petroleum has twice the energy density of coal, 48 MJ per kilogram of fuel oil versus 24 MJ per kilogram. One liter of petroleum weighs 0.88 kilograms, and there are almost 159 liters in a barrel of petroleum. That gives a weight of 139.92 kilograms per barrel of petroleum.
Coal is priced is short tons, which are equivalent to around 907 kilograms. Using density equivalence, it takes 3.24 barrels of petroleum to equal the energy content of a short ton of coal. Thus, a barrel of petroleum must cost 30.86% as much as a short ton of coal for it to be competitive for power generation.
Coal is currently priced at $43.50 per short ton, which means petroleum would have to cost $13.42 per barrel to remain competitive for electricity generation, excluding transportation costs, etc. Checking
here, in the period since the end of World War II petroleum has never been that inexpensive except for a brief period in the late 1990s.
However, petroleum was used for 20% of United States energy generation during the little-known Bandwagon Market for petroleum fired electric generation that took place between 1965 and 1973, and petroleum and coal had largely the same margins. Under some conditions petroleum might work out.
The larger issue though is that petroleum is inelastic and is still selling quite well at prices higher than those seen since 1973. I doubt they could make as much money as they do now even with petroleum being sold for electric generation.