Hydrogen Economy: Boom or Bust?

For all the renewable energy champions pointing to hydrogen as our best fuel for our future, an equal number of naysayers are more than willing to join in the debate. In a 2006 article on PhysOrg, writer Lisa Zyga referred to a study by fuel cell expert Ulf Bossel, who concluded a hydrogen economy is a “wasteful economy.” (See the attached chart.)

This chart compares the useful transport energy requirements for a vehicle powered from a hydrogen process (left) vs. electricity (right). Image Credit: Ulf Bossel.

Then there are the champions.

Remember the passionate words of television actor and hydrogen champion, Dennis Weaver, when he piloted a hydrogen-powered car from coast to coast, proclaiming hydrogen was the fuel of the future?

“If we had a hydrogen economy worldwide, every nation on earth could create its own energy source to support its economy, and the threat of war over diminishing resources would just evaporate.”

Clean as hydrogen is for fuel, leaving only water in its emissions trail, the process of producing hydrogen has historically been cost-prohibitive. Bossel’s study results were convincing:

“The large amount of energy required to isolate hydrogen from natural compounds (water, natural gas, biomass), package the light gas by compression or liquefaction, transfer the energy carrier to the user, plus the energy lost when it is converted to useful electricity with fuel cells, leaves around 25% for practical use — an unacceptable value to run an economy in a sustainable future.”

Bossel concluded spacecraft and submarines might be on the short list of hydrogen fuel candidates.

“The advantages of hydrogen praised by journalists (non-toxic, burns to water, abundance of hydrogen in the Universe, etc.) are misleading, because the production of hydrogen depends on the availability of energy and water, both of which are increasingly rare and may become political issues, as much as oil and natural gas are today,” concluded Bossel. “More energy is needed to isolate hydrogen from natural compounds than can ever be recovered from its use.”

Regardless of the negative sides of producing hydrogen, scientists continue making important discoveries. Recently, University of New South Wales scientists announced the development of a “highly efficient oxygen-producing electrode for splitting water that has the potential to be scaled up for industrial production of the clean energy fuel, hydrogen.”

A scanning electron microscope image shows the porous structure of the nickel foam used to make UNSW Australia’s inexpensive and efficient oxygen-producing electrode. The foam has holes in it about 200 micrometers across (Scale bar is 200 micrometers)

According to the press release, the hydrogen-capture technology is based on an inexpensive, specially coated foam material that lets the bubbles of oxygen escape quickly.

“Our electrode is the most efficient oxygen-producing electrode in alkaline electrolytes reported to date, to the best of our knowledge,” said associate professor Chuan Zhao, of the UNSW School of Chemistry. “It is inexpensive, sturdy and simple to make, and can potentially be scaled up for industrial application of water splitting.”

The research, by associate professor Zhao and Dr Xunyu Lu, is published in the journal, Nature Communications.

The hurdles faced in producing hydrogen are daunting ones, explained Brossel. “Ultimately, hydrogen has to be made from renewable electricity by electrolysis of water in the beginning, and then its energy content is converted back to electricity with fuel cells when it’s recombined with oxygen to water. Separating hydrogen from water by electrolysis requires massive amounts of electrical energy and substantial amounts of water.”

Zhao and Lu believe they have discovered a cost-efficient solution to this problem.

“Inefficient and costly oxygen-producing electrodes are one of the major barriers to the widespread commercial production of hydrogen by electrolysis, where the water is split into hydrogen and oxygen using an electrical current.

“Unlike other water electrolysers that use precious metals as catalysts, the new UNSW electrode is made entirely from two non-precious and abundant metals — nickel and iron.”

I look forward to reporting on scalable and cost-effective advances on hydrogen production.

However, no matter how you cut the dice, it’s simply much less efficient to produce hydrogen from electricity and then use it in battery-electric vehicles. Furthermore, hydrogen electric vehicles don’t have the theoretical performance capability that battery-electric vehicles already have today. So, while hydrogen may have a part to play in the world of energy storage (especially seasonal storage), it looks like a dead end when it comes to mainstream vehicles.

Images: Chart via physorg; electron microscope image via UNSW Australia