Until all electricity generation is provided from renewable energy sources, taking green power off the grid to make hydrogen is an inefficient use of the resource that will push up its costs and lower its environmental benefits: renewable power taken off the grid today necessarily gets replaced with a dirtier alternative (Windpower Monthly, May 2003). Yet though that fact pushes the dream of a global hydrogen economy into the far future, there are enough remote pockets of exploitable potential for the pace of wind-to-hydrogen research to be picking up. At least a dozen projects are in the works in half a dozen countries across Europe, North and South America, with a handful to be launched this year. Spain alone is already running three projects.
Pure Energy Centre (PEC) Ltd, a community/private wind-to-hydrogen project on the Scottish isle of Unst, is the latest to receive press coverage and kudos -- short listed for the St Andrews Prize for the Environment. On Unst, two 15 kW wind turbines feed power to thermal storage for heating, or directly via a DC connection to light the PEC building. Excess wind is fed to an electrolyser for conversion to hydrogen, which is then stored in high pressure cylinders, available to be converted back to electricity or be pumped into the tank of PEC's bright green hydrogen test car.
PEC considers its project to be one of the furthest along in wind-to-hydrogen, in part because it is a functioning off-grid system. Unst's remoteness makes it an ideal testing ground. The island's 3.68 MW Burra Dale wind farm already supplies the maximum amount of wind power the small grid can handle (although a grid cable is being debated to support approximately 600 MW of new onshore wind being planned around Unst).
Thousands of miles south in the Patagonia region of Argentina, the town of Koluel Kaike is part of a UN pilot project to demonstrate wind and hydrogen's ability to power the transport and other electricity needs of the town's 500 inhabitants by 2008. The huge supply of steady wind around Koluel Kaike and the 2.4 MW of current wind capacity via four Enercon turbines from Germany, coupled with an electrolyser and a small hydrogen storage facility, attracted the interest of Argentina's energy company Capex, which said in 2005 it would study the feasibility of a huge wind-to-hydrogen complex there.
Meantime, PEC is using its new found expertise to develop a commercial product called the Hypod, a six metre container with all the pieces -- electrolyser, hydrogen storage, fuel cell -- that government or public interest groups need for wind-to-hydrogen demonstrations. The Hypod's starting price tag is around EUR 430,000. PEC manager Sandy Macaulay is up-front about wind-to-hydrogen being an expensive option still in the research stages. Most hydrogen demonstration projects, such as the fuel cell buses seen on the streets of many European cities, prove their concept without using renewable hydrogen. "That leaves them open to criticisms," he says. "It leaves one to legitimately ask, what is the point?"
Systems such as PEC's, however, prove that wind is a viable source of hydrogen for heating, electricity and transport and that in some settings local needs trump high costs, especially if energy efficiency is employed. PEC has two Hypod hydrogen storage projects in the pipeline, one on the remote windswept Scottish peninsula at Knoydart.
Long way to go
"The hydrogen economy is technically possible, but we've got a long way to go to reduce energy demand before it is practical and sustainable," he says. "Every country requires energy security, however, and many will have problems matching supply with demand -- that will start to happen soon worldwide. Once you reduce your energy demand and hydrogen is linked to renewables it starts to make sense."
The European Wind Energy Association (EWEA) is adamant that linking wind and hydrogen is not desirable or necessary for the large-scale implementation of wind. "Wind and hydrogen, they are not Siamese twins," says Frans van Hulle, EWEA technical expert. "On the contrary, hydrogen is not going to make things cheaper and the large scale penetration of wind doesn't need hydrogen to be feasible." On the other hand, Van Hulle does not discount a hydrogen economy sometime down the road. Hydrogen storage may one day be an economic solution for facilitating an all-renewables power supply, though lots of conditions need to be fulfilled and technical solutions found before using hydrogen as reserve power on an electricity system is practical. "In the long run we don't want to exclude the hydrogen economy as an option," he says. "We don't want to appear to have tunnel vision."
On the Norwegian island of Utsira in the North Sea, oil company Norsk Hydro continues to run a wind-to-hydrogen system, even though the project was supposed to be wound down this year. Business development manager Ulf Hafseld explains why Hydro and Enercon, its development partner, decided to extend the experiment. "What we learned from Utsira? We feel there are some conflicts on the road to commercialisation," Hafseld says. "The main challenge is to reduce the cost somehow. We need improvements in fuel cells -- higher efficiency and lower cost -- a new generation of electrolysers, system optimisation. We need to work on all these issues."
Hafseld acknowledges that one of the biggest problems is storage. Currently, windy Utsira's two Enercon 600 kW turbines and backup hydrogen system power just ten households in what is clearly an expensive niche application. The system cost Norsk Hydro about £5 million. At a similar project in Prince Edward Island in Canada, the "buffer" electricity available from wind-produced hydrogen is estimated to cost $0.20-$0.30/kWh, from wind energy that costs $0.03-$0.06 to generate. Companies like Norsk Hydro, however, have a vested interest in seeing hydrogen succeed -- the company makes and markets electrolysers like the one used at Utsira.
Globally, researchers are working on different methods of hydrogen pressurization, and of solid state storage, such as in magnesium or organic chemical hydrides. In the United States, Stanford researcher Mark Jacobson has said his research, published in the journal Science, hypothesizes that if it can be successfully commercialised, hydrogen from wind is one of the best choices for the environment and for human health -- far preferable to hydrogen from coal, natural gas or nuclear. And PEC's Macaulay says he believes wind-to-hydrogen systems will be viable solutions, especially for remote locations, within a decade.
"They aren't commercially viable yet," he says. "They've got to be mass produced to be cheap. But there's no fuel crisis, yet. When the lights go out that's when there will be the start of a critical mass."