Aggressive pursuit of a hydrogen economy, as has been recently advocated by many environmentalists, is wrongheaded and shortsighted.

To understand why, we need to start with the basics. Hydrogen must be extracted from other materials before it can be of use as fuel. A wide variety of materials contain hydrogen, which is one reason it has attracted widespread support. Everyone has a dog in this fight.

Renewable energy is a very little dog. Environmentalists envision an energy economy in which hydrogen comes from electrolyzing water, a process that frees the hydrogen in water from its bond with oxygen. The energy used to accomplish this would come from wind. Big dogs like the nuclear industry also foresee a water-based hydrogen economy, but with nuclear energy as the power source that electrolyzes water. The trade journal Nucleonics Week boasts that nuclear power 'is the only way to produce hydrogen on a large scale without contributing to greenhouse gas emissions.'

The fossil fuel industry believes that hydrocarbons will provide most of our future hydrogen. They already have a significant head start. Almost half of the world's commercial hydrogen now comes from natural gas. Another 20 percent is derived from coal.

The automobile and oil companies are betting that petroleum will be the hydrogen source of the future. It was General Motors, after all, that coined the phrase 'the hydrogen economy.'

What does all this mean? A hydrogen economy will not be a renewable energy economy. For the next 20 to 50 years, an overwhelming percentage of our hydrogen will be derived from fossil fuels or with nuclear energy.

Consider that it has taken more than 30 years for the renewable energy industry to capture 1 percent of the transportation fuel market (ethanol) and 2 percent of the electricity market (wind, solar, biomass). Renewables are poised to rapidly expand their presence. A hydrogen economy would be a potentially debilitating diversion: The more aggressively we pursue hydrogen, the less aggressively we will pursue more beneficial technologies.

To be successful, a hydrogen initiative will require the expenditure of hundreds of billions of dollars to build an entirely new energy infrastructure (pipelines, fueling stations, automobile engines). Much of this will come from public money. Little of this expenditure will directly benefit renewable energy initiatives. Indeed, it is likely that renewable energy will claim about the same share of the hydrogen market in 2040 as it now has of the transportation and electricity markets.