Hydrogen Not Efficient for Energy Storage

The annual fuel cell conference of the European Fuel Cell Forum was held in Lucerne, Switzerland, last week. Much of the sentiment from the conference in regard to hydrogen energy storage was compiled in this Reuters newsreport:

When environmentally friendly wind electricity is used to generate hydrogen, only one-quarter of the energy generated by the wind turbine is eventually used to move a car. The rest is lost during transport and energy conversion, said Ulf Bossel of the European Fuel Cell Forum, which held its annual fuel cell conference in Lucerne, Switzerland, last week.

"With hydrogen energy you only have 25 per cent efficiency to turn wind power to [car] wheel power," he said. It's much more efficient to transport that electricity directly into a car battery, via the grid, and use 90 per cent of its power."

Hydrogen is being discussed at the conference because it is one of the fuels for cells that can generate electricity and heat in an electrochemical conversion.

....Bossel said most renewable energy will be harvested as electricity through wind and solar power and should be used directly.

But he accepted that today's economy is based on fuels and cars will need some liquid fuel for long journeys, rather than recharging batteries every few hundred kilometres.

Even when this liquid energy is made from biomass, it makes sense to turn it into a biodiesel rather than hydrogen, said Wim van Swaaij, professor of thermo-chemical conversion at Netherlands' Twente University.

Biofuels are easy to handle, like today's fuels. Hydrogen, in its pure form, needs to be stored under high pressure which also consumes energy. Biofuels themselves contain hydrogen but in a much more stable form.

"Through steam reforming technology we can turn 40 to 50 per cent of the original fuel content in biomass into biofuel. The percentage is even higher for hydrogen, 50 to 60 per cent, but we will also have to store it and biofuels are the easiest and most efficient way to store it," Van Swaiij said.

The carbon particles in the biofuel will not make a net contribution to heating up the Earth through the greenhouse effect if the fuel is harvested from biomass, because the plants consume carbon dioxide as they grow, Van Swaaij added.

Bossel also said that producing hydrogen, either through electrolysis using nuclear or renewable electricity, or refined from biomass or fossil fuels, requires massive amounts of water. One kilogram of hydrogen requires nine litres of water.

In capitalist countries, the market will decide efficiencies based upon pricing--supply and demand--within the context of government regulation. We should all hope that government does not chase the wild albatross of hydrogen storage too much farther. Eventually nanotechnology and materials technologies may make hydrogen viable, economically. At present it would be smarter to bank on alternatives, such as batteries, supercapacitors, and biofuels such as bio-butanol and biodiesel.