With the ever-increasing addition of wind and solar renewable energy to the traditional electric grid, the need for energy storage also grows. A recent study projects the value of energy storage for wind and solar integration worldwide to exceed $30 Billion by 2023 . Hydrogen from electrolysis is a promising technology for renewable energy capture as it has the capability to store massive amounts of energy in a relatively small volume. In addition, electrolysis can also provide ancillary services to the grid such as frequency regulation and load shifting resulting in multiple value streams. The hydrogen produced can alternatively be injected into the natural gas pipeline (thus making that energy carrier more green), in the production of high value chemicals such as ammonia, in upgrading of methanization-produced biogas, or used as a transportation fuel.
Europe in particular has been committed to these pathways and making heavy investment in both materials research and system design and development as well as technology demonstration. In Germany, hydrogen is looked upon as a key part of the energy storage solution under “Energiewende,” their national sustainable energy transition plan. Hydrogen provides a unique link between the electric and gas grid infrastructures (often referred to as “Power-to-Gas”). Germany is also considered the global leader in biogas energy generation, with 18,244 GWh of generation in 2012 forecasted to grow to 28,265 GWh by 2025 .
Water electrolysis has benefits over other hydrogen generation technologies due to the lack of carbon footprint when integrated with a renewable source of energy. Specifically, proton exchange membrane (PEM) electrolysis is a promising technology for hydrogen generation applications because of the lack of corrosive electrolytes, small footprint, and ability to generate at high pressure, requiring only water and an energy source. Several companies have already announced plans to develop megawatt (MW) commercial scale PEM electrolysis units in the 2014–2015 timeframe for these applications. There have also been recent announcements of large scale renewable energy storage project based on electrolysis.