Could MIT's Work On Solar Electrolyzers Help Solve Fuel-Cell EV Hydrogen Woes?
By John O'Dell August 24, 2010
Yes, hydrogen fuel cells vehicles in any meaningful volume are still years, if not decades, away, and yes, even when the engineers get all the bugs worked out of the fuel cell system, the big question still looms: Where's the hydrogen gonna come from and how clean will it be?
Fuel-cell electric cars such as Honda's FCX Clarity would get a huge boost with availability of clean, home-produced hydrogen fuel.
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If it is made and compressed for fuel cell use with electricity from coal-fired powerplants, hydrogen won't be very clean (no tailpipe emissions, but lots of nasty stuff pouring out of the powerplants' smoke stacks). Even if electricity from natural gas-fired generators enters the equation there still will be emissions to deal with.
But if the hydrogen can be produced using electricity from solar or hydro power, and if the cost of making the stuff can be lowered to the point that home-based hydrogen makers and pumps can be employed, well, then we've got a new ballgame.
Researchers at Massachusetts Institute of Technology have been working on one aspect of the home energy problem for a while now and this week announced what may lead to a breakthrough in making such systems affordable.
They've developed a relatively inexpensive nickel-borate catalyst that, they say, can replace the expensive, short-lived and toxic-to-produce platinum catalysts that are crucial to the devices, called electrolyzers, that separate hydrogen from tap water (or rain water, pond water, river water,etc.)
The MIT researchers now say their catalyst is 200 times more efficient than platinum catalysts. The university has licensed the catalyst technology to a company called Sun Catalytix ,which says it is still about two years away from commercial applications.
The idea is to tie the electrolyzer - which uses an electrical current and catalysts to separate water into its constituent parts, hydrogen and oxygen - to a rooftop photovoltaic system that uses solar energy to produce clean, renewable electricity.
The study that led the MIT folks to develop the catalyst - which was first announced earlier this year - centered on making electricity for home use by feeding excess power from he rooftop solar system the power to the electrolyzer and storing the hydrogen and oxygen is produced for use at night - when the sun was down and the solar panels dormant.
The stored hydrogen and oxygen produced during the day would be released into a home fuel cell at night, where it would be converted (by passing through the fuel cell's catalyst) into a flow of electrons that could power household equipment. A byproduct would be distilled water (the recombined hydrogen and oxygen, minus their electrons) for drinking.
Someone smarter than we can do the cost-benefit calculations, but it also would seem seem possible to store some of the home electrolyzer's hydrogen - pressurized by a pump run on electricity from the solar array - for use overnight to fill the tanks on a parked fuel cell car so it would be ready to go each morning.
John O'Dell, Senior Editor
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