Hydrogen and fuel cells: fake promises?

"The question is no longer whether this technology works, but when it will be competitive," Energy Commissioner Andris Pielbags said as he unveiled the result of the CUTE project.

About a year ago, a group of MEPs presented a Green Hydrogen Charter urging the EU to mobilise all forces to shift to a hydrogen economy by 2025 (EurActiv 13/09/05). MEPs clearly expressed themselves in favour of a hydrogen economy based on renewables.

In the US, the Bush administration has earmarked $1.8 billion over five years for a Hydrogen Fuel Initiative and a complementary FreedomCAR project. The EU, the US and other partners are working together in an "International partnership for the hydrogen economy".

However, hydrogen still faces a number of criticism, not least from the scientific community.

Ulf Bossel of the European Fuel Cell Forum, an organisation that supports technical and scientific advances on fuel cells, challenges what he calls 'the hydrogen illusion'.

"Hydrogen is clean only if it is made from renewable electricity," says Bossel. But he adds that if a hydrogen-based economy becomes a reality, it will be characterised by a massive increase in demand for electric power, which he says is unlikely to be met by renewables alone.

According to Bossel, a substantial part of the increased demand for power will therefore need to come from coal-fired or nuclear power plants with all the known consequences for the environment and for safety.

In addition, he says a substantial amount of energy is lost when the electricity is converted to hydrogen for storage in a fuel cell and subsequently converted back into electricity.

"About three quarters of the original energy is lost for electrolysis, compression or liquefaction, transportation, storage, transfer and re-conversion back to electricity with fuel cells," the Fuel Cell Forum said in a statement.

According to Bossel, this is because "a synthetic energy carrier cannot be more efficient than the energy from which it is made. Renewable electricity is better distributed by electrons than by hydrogen."

However, hydrogen promoters say that fuel-cell vehicles are just as efficient, if not more efficient, than conventional engines. "Internal-combustion engines in today's automobiles convert less than 30% of the energy in gasoline into power that moves the vehicle," according to Shell Hydrogen.

"Vehicles using electric motors powered by hydrogen fuel cells are much more energy efficient, utilising 40-60% of the fuel's energy," it points out.

According to Shell Hydrogen, the biggest challenge is financial, not technical. "From a vehicle perspective, funding the transition from expensive prototypes to affordable mass production will be the key issue".

Shell estimates that Fuel Cell Vehicles can become competitive when annual production reaches one million globally. "Through the combination of the technical and manufacturing advances anticipated over the next five years, with the build-up of a reasonable global production over the following five to ten years, we believe attractive and affordable FCVs can become a commercial reality," Shell says.

Other criticisms relate to the environmental impacts of using hydrogen in the transport sector. In a recent review of scientific studies, British researchers found that contrary to most expectations, hydrogen is an indirect greenhouse gas with a potential global warming effect.

The researchers, led by Richard Derwent from the Centre for Environmental Policy at Imperial College London, said this occurs because emissions of hydrogen lead to increased burdens of methane and ozone and hence to an increase in global warming. However, they said that the climate effects would still be considerably less than in a fossil fuel economy.