What is the Efficiency of Solar-Powered Fuel Cell Vehicles?

I just read a news release on SMUD’s PV installation providing hydrogen (H2) via electrolysis for a fleet of fuel-cell vehicles. I made a feeble attempt, using Wikipedia, to figure out how much solar energy was captured, how much H2 was produced and how far the cars would travel after a typical day’s charge. I failed. My question: What is the overall efficiency (in a well-to-wheels format) of this PV/FC configuration. –Bryan B, Wylie, TX

Bryan, you ask a good question and I had to turn to hydrogen expert and CEO of H2Gen Innovations, Sandy Thomas, Ph.D. to answer your question. Here’s what he said:

“The efficiency of hydrogen production is relatively low: 75% electrolysis efficiency x 90% hydrogen compression efficiency x 50% PEM fuel cell efficiency X 92% electric motor efficiency = 31% system efficiency. Only 31% of the solar or wind electricity makes it to the wheels of such a car. (Still a heck of a lot better than the 12% to 15% of crude oil energy that makes it to the wheels of a conventional car!) But if the grid cannot absorb wind or solar electricity at any moment, it is better to capture 31% of this zero fuel cost, zero emission energy as a fuel for a zero emission FCV than to waste it.”

And hydrogen fits in neatly when the generation of renewables does not match the need of the electric grid and cannot be dispersed economically elsewhere. For instance, many wind regimes are at night when the electric utilities least need the power, so the excess electricity that the electric grid cannot absorb could be directed to electrolyze water (break it apart to isolate the hydrogen) to power vehicles or for stationary electric generation.

I have been considering using solar and wind myself to provide the hydrogen for my PEM fuel cell that augments power for my VA office — looking at these calculations makes me more interested.

Previous articleTrina Stops Development of Polysilicon Production Facility
Next articleTime for an International Renewable Energy Agency?
Scott, founder and president of The Stella Group, Ltd., in Washington, DC, is the Chair of the Steering Committee of the Sustainable Energy Coalition and serves on the Business Council for Sustainable Energy, and The Solar Foundation. The Stella Group, Ltd., a strategic marketing and policy firm for clean distributed energy users and companies using renewable energy, energy efficiency and storage. Sklar is an Adjunct Professor at The George Washington University teaching two unique interdisciplinary courses on sustainable energy, and is an Affiliated Professor of CATIE, the graduate university based in Costa Rica. . On June 19, 2014, Scott Sklar was awarded the prestigious The Charles Greely Abbot Award by the American Solar Energy Society (ASES) and on April 26, 2014 was awarded the Green Patriot Award by George Mason University in Virginia.

No posts to display