by Richard T. Stuebi
Although much of the ink these days about innovative vehicles relates to plug-in hybrids, work continues to explore the potential for hydrogen-based fuel cells to play a key role in the transportation sector — particularly in light of the recent decision by Congress to reauthorize funding for hydrogen autos.
Admittedly, as hydrogen critics and skeptics are quick to point out, the vision for personal automobiles running on hydrogen is very long-term and thus quite murky due to a number of factors, perhaps most notably the lack of a ubiquitous hydrogen refueling infrastructure. The challenges facing hydrogen vehicles are real, but for fleet vehicles with limited service radii, the lack of refueling infrastructure is less of a problem, as one dedicated refueling system can fit the bill. As a result, fleet vehicles – especially inner-city buses – are the primary focus of current testing activities for hydrogen fuel cells in transportation.
Of course, to achieve the full environmental benefits of the hydrogen economy vision the hydrogen will need to be derived by electrolyzing water via renewably-sourced electricity (e.g., from the sun or the wind) to power the electrolyzer.
Although conceptually straightforward, renewably powering electrolyzers turns out to be a non-trivial challenge. This is mainly because solar and wind electricity voltage and current are highly variable, and the electronics of the control systems in electrolyzers tend not to like fluctuations in input power.
To address this challenge, a team here in Cleveland is spearheading a project to install a solar/wind-powered electrolyzer to generate hydrogen from Lake Erie water, with the hydrogen to supply a refueling station that will power a fuel cell bus serving Cleveland-area riders.
With seed funding from the Cleveland Foundation, the project is being managed by the Ohio Aerospace Institute, and the team includes NASA’s Glenn Research Center in Cleveland, Cleveland’s Regional Transit Authority (RTA), the Great Lakes Science Center in Cleveland, Cleveland-based Parker Hannifin (NYSE: PH), and United Technologies (NYSE: UTX). The Great Lakes Science Center is already home to a 225 kw wind turbine and a 32 kw photovoltaics installation, and will be home to the electrolyzer-fed fueling station. RTA will run the fuel cell bus on the recently-renovated Euclid Corridor. United Technologies will be providing the fuel cell bus, and Parker Hannifin is providing key control systems for the fueling station. If all goes well – meaning, primarily, raising an additional $1 million or so to fully complete the project – the hydrogen fueling station and fuel cell bus will operate on a demonstration basis in a couple of years.
Of particular note, NASA is providing the intellectual expertise in developing the algorithms for controlling the electrolyzer to match the variable input power from the solar and wind generating systems. This expertise comes from considerable mission experience, in which photovoltaics systems generate electricity from the sun to power the spacecraft, and energy storage and charge control systems must accommodate power supply interruptions as planetary bodies transit in front of the sun.
To the team’s knowledge, because managing the intermittency of electricity supply in electrolyzer operation is non-trivial, there is only very limited experience with renewable electrolysis for hydrogen production, and virtually none involving more than a little bit of hydrogen production daily. So, this Cleveland project could be an important step along the path to developing truly carbon-free hydrogen-fueled transportation solutions.
As the Fellow for Energy and Environmental Advancement at the Cleveland Foundation, Richard T. Stuebi is on loan to NorTech as a founding Principal in its advanced energy initiative. He is also a Managing Director at Early Stage Partners, and is the founder of NextWave Energy.