The simplest molecule presents the best opportunity for energy. With global energy demands projected to rise 66% by 2030, the world desperately needs alternatives to fossil fuels. Hydrogen power, a recent media phenomenon, presents an enticing alternative – one whose development reaches much further back than most imagine. -When people hear ‘hydrogen power,’ they don’t realize that we’ve been working on it for 25 years, says Trygve Riis, the Norwegian chairman of the International Energy Agency’s Hydrogen Implementation Agreement (IEA-HIA). -The world has already made significant progress in hydrogen production, storage, distribution, and safety.
Riis spoke at a press briefing in Washington, DC, where he unveiled the IEA-HIA’s 25th anniversary report, In Pursuit of the Future: 25 Years of IEA Research Towards the Realisation of Hydrogen Energy Systems.
"Hydrogen is one of the few options we have for meeting energy demands without increasing global carbon dioxide emissions,” said Giorgio Simbolotti, PhD, an IEA program officer who also spoke at the briefing.
In 2004, governments worldwide will spend about $1 billion (US) on hydrogen research and development; corporations will spend another $5 billion (US) – both figures all-time highs. Much of this investment is spurred by the HIA’s drive to develop 'baseline' hydrogen technologies.
"We have an ambitious vision, but the challenges are significant, said Riis. The first challenge is production. Today the world produces roughly 40 million tonnes of hydrogen per year, most used for making ammonia and, ironically, for refining fossil fuels. If used for energy, the world’s annual hydrogen output would satisfy just 0.1% of the world’s energy needs," said Simbolotti.
Hence the need for large-scale hydrogen production. Strategies range from the old - coal gasification, developed in the 19th century – to the new – huge tanks of algae that gobble carbon dioxide and spew out hydrogen.
In the near-term, fossil fuels present the most viable feedstock. The technology to turn carbon-based fuels into hydrogen is proven and inexpensive. While cleaner than burning, these hydrogen-producing techniques, including the gasification of coal and the reformation of natural gas, still produce greenhouse gases. A cleaner long-term solution is needed.
Thermochemical production is one possibility. The process, which splits water molecules into hydrogen and oxygen, became the IEA-HIA’s first project, or 'task' in 1977. Since then, the consortium has fostered dozens of projects, many focused on the sulphur/iodine process. A 3-step chemical reaction proposed in the late 1970s, sulphur/iodine production became reality when IEA-HIA members achieved a fully operational bench-scale system in the early 1990s. The IEA-HIA also funds several electroysis projects, which split water by passing electricity through it. One electroysis 'stack' ran continuously for 40 days, a milestone.
While these two methods present ready opportunities for small-scale deployment, a truly clean, renewable source awaits in the future: solar-to-hydrogen. Its potential is so high that 40 groups from academia and industry have been hammering out solar production strategies since IEA-HIA’s inception in 1977. “Many believe solar-to-hydrogen is the ultimate energy solution,” said Riis. In some designs, sunlight powers conventional photovoltaic cells, which in turn drive electroysis. In others, green algae and cyanobacteria gulp carbon dioxide and spew out hydrogen.
After production, storage becomes the main concern. Current state-of-the-art demonstration busses and cars store hydrogen like gasoline, in tanks.
But in 1995, research teams began a push for a much more advanced storage system: metals. As the smallest molecule, hydrogen packs into tight spaces inside the latticework atomic structure of metal. Just like a soggy sponge soaking up water, a block of solid state hydride absorbs hydrogen. Heating the metal releases hydrogen gas. In 2000, IEA-HIA researchers achieved their goal of making a hydride that contains 5% hydrogen (by weight). Researchers are now striving for metals with 20% or higher hydrogen-to-weight ratios.
A plentiful supply of metal ore makes hydrides attractive, as does their low operating temperature. And unlike traditional batteries, hydrides do not lose efficiency over time. Safety is also high: in the 1970s, researchers demonstrated this by firing bullets into hydride blocks.
Other solid-state approaches use advanced carbon materials, such as graphite nanofibers. But all solid-state solutions, while hotly pursued, are expensive. “The key to widespread use will be pushing the price down,” said Riis.
Ultimately, though, hydrogen power will succeed only when it can be distributed to users and converted back into energy. Case studies exploring various distribution schemes include fuel cells that produce electricity from an onboard hydride block. Others employ solar-powered or liquid hydrogen fuel stations. One test system slashed vehicle refuelling times to three minutes while reducing boil-off loses to less than 10%. Other demonstration projects have put hydrogen-fueled cars, trucks, and busses on the road in several countries.
Expanding access to the masses is a long-term prospect, said Riis. It will require continued international cooperation for another quarter-century and beyond. He optimistically pointed to the imminent expansion of the IEA-HIA and closer cooperation with Japan, which invests more in hydrogen research than any other country. The US Department of Transportation also plays a key role in hydrogen’s future, he said, adding that research led by Norwegian conglomerate Norsk is a prime example of the expanding role for corporations in the IEA-HIA.
About the International Energy Agency’s Hydrogen Implementation Agreement:
Launched in 1977, the agreement coordinates hydrogen energy research around the globe. Thirteen counties and one confederation are now party to the HIA: Canada, the European Commission, Iceland, Italy, Japan, Lithuania, Netherlands, Norway, Spain, Sweden, Switzerland, United Kingdom, and the United States. Several other countries are considering joining. Ideas for projects, or 'tasks', bubble up from the member countries in a truly decentralized, bottom-up approach, said Riis. “It all depends on the member countries and their ideas,” said Riis. The IEA itself formed in 1974, after the first global energy crisis, to promote worldwide energy stability, environmental protection, and economic development.
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