Hydrogen storage, the process using excess energy from renewable power sources to create hydrogen, is becoming increasingly popular in Europe, a new report shows.

The report on the public consultation on the Fuel Cell and Hydrogen Joint Undertaking (FCH JU) launched by the European Commission last summer, gauges opinions from 127 individual citizens, research organizations and companies from 22 European countries on the future of the hydrogen fuel cell industry in Europe.  95% of respondents expressed support for hydrogen as a storage medium for renewable energy.

The idea behind hydrogen storage is simple: when electrical supply from intermittent energy sources such as wind turbines or photovoltaic solar cells is greater than the electrical load on the grid, the excess energy is used to create hydrogen through the electrolysis of water. That hydrogen can be compressed and stored in tanks and natural gas reservoirs, or pumped through natural gas pipelines. The gap between production and grid capacity is often significant: Germany’s wind energy trade association estimates that the German power grid was unable to utilize 150 gigawatt-hours of electrical energy from wind turbines in 2010 because it was already operating at full load.

For a concrete example, according to a position paper submitted in response to the consultation by the Swedish firm Apoidea AB, wind energy production in the north of Sweden is projected to reach 45 billion kWh by 2020. However, the Swedish national grid says it will only be able to add a maximum of 15 billion kWh of transfer capacity. Apoidea proposes to use the excess energy for water electrolysis and distribute the resulting hydrogen to Germany or Denmark, which have more advanced hydrogen infrastructures. The heat produced by the electrolysis process could also be used for domestic heating.

Hydrogen storage is already a reality. Hydrogenics Corporation, based in Mississauga, Ontario, has installed electrolyzers at 35 fueling stations worldwide. Its HySTAT 60 electrolyzer can generate 130kg of pure hydrogen per day. The company also recently announced it is installing a 2 MW “power-to-gas” energy storage system in Falkenhagen, Germany, for the power and gas company E.ON. The facility will be able to store over 20 MWh of energy over a 24-hour period, according to Hydrogenics CEO Daryl Wilson, and will produce about 360 cubic meters of hydrogen per hour.

The German multi-national firm Siemens is also developing a large-scale electrolysis system.

A Hydrogenics HydroSTAT electrolyzer