German test plant aims to store wind power as gas-grid hydrogen

As they bring more renewable energy sources online, utility companies face a double challenge: how to keep the grid stable despite the ups and downs of wind and solar energy, and how to store excess energy from renewables for times when demand is high.

That’s why E.ON plans to develop a pilot energy storage plant in Falkenhagen in the northeast of Germany. The facility, being built at a cost of more than €5 million ($6.8 million), will be designed to convert wind power into hydrogen that can be stored in the country’s gas grid for use when needed.

Set to begin operating in 2013, the plant will use electrolysis — running an electrical current through water — to produce  an expected 360 cubic meters of hydrogen each hour. That hydrogen will be fed into Germany’s Ontras gas pipeline system to be used just like natural gas, essentially turning the gas grid into an energy storage system.

Currently, up to 5 percent hydrogen can be added to the natural gas grid without problems. In the medium term, that percentage is expected to rise to 15 percent … which would make it possible for all of the renewable energy generated in Germany today to be stored as hydrogen in the nation’s gas grid. However, demand for that kind of capacity isn’t expected until most of the country’s power comes from renewable sources, most likely a few decades from now.

“We need new storage capacities so that we can further increase the share of weather-dependent wind power in our generation portfolio in coming years,” said Klaus-Dieter Maubach, a member of the E.ON board responsible for technology and development. “Using the existing gas infrastructure to store hydrogen is a promising approach in the long run, enabling us to combine our strengths as a power and gas company.”