Energy sources and the storage of that energy present basic problems to our civilization. Carbon-based fuels cause global warming by releasing CO2 and other pollutants. Nuclear power is safe, clean, and unlimited. But it produces indestructible radioactive waste, which is a carcinogenic pollutant if it's accidentally released into the atmosphere. Waste storage must be both stable and reliable against leakage for thousands of years.
For waste storage, I propose drilling a five-mile-deep hole next to each reactor and dropping in the waste to fill the bottom mile. The ocean is less than four miles deep, so there can be no pollution by seepage. A concrete plug prevents upward diffusion. There would be no remanufacturing, no transportation, no legal obstacle, and no depository problems because the waste would never leave the property of the reactor that generates it.
Five miles is well within the range of drilling technology. The slip displacement of earthquakes is only a few meters even at the actual centers. Earthquakes cause damage by radiated vibration, which won't harm the storage hole. The only risk is of a volcano spontaneously forming at the hole site, an extremely improbable event.
Today, substantially all stored fuel is petroleum-derived, natural gas, and coal, all of which are CO2 generators that produce global warming. The most pollution-safe stored fuel is hydrogen.
Hydrogen and oxygen gases are generated by passing electricity through water. For energy storage, the oxygen is released into the atmosphere, without harm, and the hydrogen is saved for later burning.
Hydrogen gas is odorless, nontoxic, nonpolluting, and nonexplosive. Like gasoline, it burns in air, but it can't explode. Hydrogen can't decompose into something else. Released hydrogen rises and floats away, and it's totally nonpolluting. When hydrogen burns, the result is pure water (usually steam) with zero CO2. A hydrogen plus air mixture is indeed explosive, as is the gasoline vapor plus air mixture whose explosions now power your car.
Existing gasoline and diesel engines and gas turbines can be converted to hydrogen by a carburetor adjustment. Hydrogen is an ideal fuel for the fuel cells of an electric car and other electricity needs.
One fringe benefit of hydrogen energy storage is that there's no need to transport the fuel at all. The energy to be stored is delivered over existing electric wires to simple tanks where it divides water into hydrogen and oxygen. The oxygen is released into the atmosphere and the hydrogen is stored.
Another fringe benefit is the elimination of our dependence on OPEC for energy.
The single major obstacle in the way of conversion to hydrogen energy is that we don't yet have a good portable way to store the hydrogen equivalent of an automobile tank of gasoline, or an airplane tank of jet fuel. At one extreme, we can store hydrogen near atmospheric pressure in big tanks as we now do for illuminating gas. At the other extreme, we can compress hydrogen in heavy steel tanks to several thousand lb/in.2, as we have done for industrial use for many years. In between, we can use scuba-diver and spherical fiberglass tanks.
None of these storage methods is suitable for a car or airplane. The U.S. Department of Energy and the Defense Advanced Research Projects Agency have small hydrogen projects under way. But the value of a lightweight, small-volume storage system is so enormous that a massive, high-priority research project should be funded by Congress. Inexpensive, pollution-free, OPEC-independent energy is right at our fingertips!