A recent theory for cold fusion is that deuteron stripping reactions (1935 discovery by Oppenheimer) are occuring with Nickel-64 isotope. This would produce 8 MeV for each reaction for the 1% of the nickel that is nickel-64. 80,000 eV for each atom of nickel. 1250 times more energy density by weight than any chemical reaction.
The Earth’s crust is 75 parts per million nickel. Only iron, oxygen, silicon and magnesium are more common.
World Nickel production is about 1.42 million tons per year.
So if the Nickel-64 theory is correct and can be perfected then Nickel production would need to be increased. 1 ton of oil is equal to 7.3 barrels of oil. 11.7 million tons of oil per day is used in the world. 9000 tons of nickel that is totally used would equal that energy. 3.5 million tons of nickel per year used for perfected deuteron stripping reactions would equal all of the oil we use now.