|The Wind2H2 project. Click to enlarge.|
Xcel Energy and the US Department of Energy’s National Renewable Energy Laboratory (NREL) a pilot facility that uses electricity from wind turbines to power electrolyzers to produce hydrogen, which is then compressed and stored at 3,500 psi.
The Wind2H2 project is designed to examine the system integration issues with wind-hydrogen production, compression, storage, and use. The project integrates wind turbines directly to the electrolyzers testing both AC and DC connections. The hydrogen is used to power a Hydrogen Engine Center (HEC) genset. (Earlier post.) A hydrogen fueling station for vehicles is planned for the future.
Today we begin using our cleanest source of electricity—wind power—to create the perfect fuel: hydrogen. Converting wind energy to hydrogen means that it doesn’t matter when the wind blows since its energy can be stored on-site in the form of hydrogen.
By marrying wind turbines to hydrogen production, we create a synergy that systematically reduces the drawbacks of each. Intermittent wind power is converted to a stored fuel that can be used anytime, while at the same time offering a totally climate-friendly way to retrieve hydrogen, to power our homes and possibly cars in the future.—Richard Kelly, Xcel Energy chairman, president and CEO
Currently, there are limitations to both wind power and hydrogen. Wind farms only generate electricity when the wind is blowing, which is about one-third of the time in the United States. This creates the need for backup generation, which is usually fossil-fueled. Hydrogen production currently relies on the reforming of natural gas, or on electrolysis of water—energy-intensive processes that result in greenhouse gas emissions (depending on the source of the electricity).
NREL assessed the economics of wind-powered hydrogen production and concluded that while the near-term cost is around $4.03 per kg of hydrogen, long-term costs could drop down to $2.33/kg hydrogen.
NREL also concluded that it would be feasible to produce 154 billion kg of hydrogen per year from Class 4 and higher wind in the United States. Current transportation fuel usage is around 140 billion gallons per year.
The project allows our researchers to compare different types of electrolyzers and work on increasing the efficiency of a wind to hydrogen system. And, it has the potential to point the way to a completely emissions-free system of making, storing and using energy.—Dan Arvizu, NREL director
NREL and Xcel Energy expect to offer a public update on the operation of the project around the middle of 2007. Results will also be shared with the Hydrogen Utility Group, made up of Xcel Energy and nine other utility companies interested in hydrogen’s future role in the utility industry.
The Xcel-NREL Wind2H2 project is one of several projects in the US sponsored by the DOE to investigate the combination of wind power and hydrogen production. (Earlier post.)