Hydrogen is more than plentiful; there are two atoms of H for every atom of oxygen in each molecule of water.

There’s more water than land on Earth’s surface, and the water is not difficult to find.

But there’s a sticking point. Free hydrogen in the atmosphere, produced largely by radioactive decay, floats to the upper atmosphere and off into space.

The challenge becomes detaching hydrogen from compounds, like water.

When hydrogen is incorporated into water it’s fairly placid. Water is used to extinguish fires, after all.

So hydrogen in the form of water is not a feasible fuel, unless it can be heated to the point where hydrogen nuclei fuse, which yields way too much energy and a prohibitively short time.

Water is the inevitable raw material for hydrogen production, but separating the two elements requires quite a bit of energy.

Currently, most hydrogen is produced from methane, a carbon atom linked to four hydrogens.

Methane is heated with water to create carbon dioxide and hydrogen molecules. This is called "steam reforming."

Another method is to use electricity to break water into oxygen and hydrogen.

The real sticking point in all of this is thermodynamics.

As is probably obvious, it takes more energy to liberate the hydrogen than the hydrogen contains.

The Cato Institute, which typically stands with the status quo, is not optimistic about the hydrogen economy.

A Cato briefing paper points out that steam reforming is 30 percent efficient — meaning that much more energy goes into production than comes out as hydrogen fuel.

Burning the methane stock would be more efficient.

And ultimately Cato (the institute, not the famous Roman) estimates that powering all U.S. vehicles with fuel cells would require something like 130 billion pounds of hydrogen.

It would take about 15 trillion cubic feet of methane to make that much hydrogen.

Electrolysis is similarly energy intensive.

Storing and transporting all of this extremely flammable hydrogen presents another galaxy of problems.

But we cannot choose between hydrogen versus no hydrogen. If we don’t burn hydrogen, the energy has to come from somewhere else.

What Cato does not address is the energy efficiency of a gasoline-powered economy. Internal combustion engines are notoriously inefficient.

Much of the energy in the gasoline is discarded as waste heat.

Extracting petroleum, transporting it to refineries, running the refineries and transporting the gasoline also consume loads of energy.

Fossil fuels have worked so far because the energy necessary to produce them is miniscule compared to the millions of years of solar energy that coal, oil and gas contain.

Likewise, the power to extract hydrogen is nothing compared to the formation of the solar system.

Which makes sense, because we’re tapping into the energy of the gathering hydrogen ball of the future sun, rather than the sun’s later and relatively feeble radiation.

Who expected that to be easy?