Hydrogen As Energy Storage

Hydrogen isn’t just used as a fuel; it’s also used as storage. As the United States continues to undergo an energy transition, it is increasingly difficult to find the place to use all the excess renewable energy. Solar and wind are good clean energy sources, as long as the sun is out and the wind is blowing, but these sources lack downtime capacity. An example of this problem is the “Duck Curve”, which refers to a California study that highlights how solar energy is very common during the day, a period of relatively low electricity demand, but sparser in the evenings, when peak electrical demand is reached. A similar problem occurs for other renewable sources, like wind and hydropower. The question facing policymakers, engineers, and businesses is how to store that clean energy in a way that can outsmart problems like the Duck Curve.

Electrical batteries are one solution to the problem of intermittent energy supply, but our current battery system faces difficulties in storing the energy required. Operators need a large amount of stored clean energy during non-peak production hours to support a modern electrical grid and the U.S. currently doesn’t have the battery capacity to store and use the clean electricity we use during the day to power our homes and cities during the night.

One answer to this problem is hydrogen as a storage device for energy. Hydrogen allows vast quantities of clean energy to be stored for long durations for use in peak demand and seasonal energy balancing. Hydrogen can be generated from electrolysis using excess renewable electricity during peak production hours. Once produced, hydrogen can be used in stationary fuel cells for power generation or stored as a compressed gas, cryogenic liquid or wide variety of loosely bonded hydride compounds for longer-term use. When the sun sets and the renewable energy stops coming in, grid operators can turn on hydrogen generators and keep the lights on until the energy supply recovers in the morning.

While liquified hydrogen can be stored in manufactured storage tanks, it is often more economically efficient to use natural geological formations. Naturally occurring salt caverns are one of the best ways to store liquified hydrogen. Because of this, many of the early hydrogen storage projects are expected to occur in regions with favorable geology, such as the southern U.S. or the Midwest U.S.

Hydrogen also offers the potential for seasonal energy storage, in addition to short term load balancing. As the world increasingly transitions to renewable energy, winter months will strain electrical grids as less sunlight will reach the solar farms. To counter this issue, hydrogen can be created via electrolysis with abundant solar energy in summer months, and then used to fuel the grid during the cold and cloudy winter months. Hydrogen is the only viable carbon neutral seasonal storage option currently, and as the world decarbonizes it will become increasingly important in electrical grids.

To learn more about how FCHEA members are involved in hydrogen storage projects check out our previous blogpost on the subject here or subscribe to the Connections newsletter below.