American Scientist

To the Editors:

The concept of using “green” hydrogen in a fuel-fired power plant, as discussed in Lee S. Langston’s article “Generating a Cleaner Future” (Technologue, March–April), leaves me with a basic question: If green hydrogen is created by the electrolysis of water, will it not require more electrical power from the grid to make the hydrogen than can be returned to the grid by burning the hydrogen as fuel?

Using the most efficient processing available today, the electrolysis of water would take more than twice as much power as the resulting burning of hydrogen would provide. And no matter what improvements can be made to the efficiencies of the electrolysis and combustion processes, it will always take more power to produce the hydrogen than can be generated from burning it.

Unless there is a means to create hydrogen other than the electrolysis of water, what is the reasoning that leads one to pursue the use of hydrogen as a fuel in a gas-fired power plant?

W. M. Goldberger
Columbus, OH

Dr. Langston responds:

You are certainly correct that the process of electrolyzing water to produce hydrogen will require electrical power—from somewhere. The key words in my explanation are “created from a surplus of renewable energy.” One problem with wind- and solar-generated electricity is what to do with those electrons when there is no market for them. For instance, Denmark has on occasion resorted to paying neighboring countries to take surpluses of its extensive wind power electricity rather than shut down whole arrays of its wind turbines. Germany has had a similar problem with surplus solar power generated in its southern states. Using that extra energy to create hydrogen would be a way to perpetuate green power.