Characterizing Hydrogen Storage Potential in U.S. Underground Gas Storage Facilities. Issue 3 (10th February 2023) - Lackey, Greg
Abstract: Underground hydrogen storage is a long‐duration energy storage option for a low‐carbon economy. Although research into the technical feasibility of underground hydrogen storage is ongoing, existing underground gas storage (UGS) facilities are appealing candidates for the technology because of their ability to store and deliver natural gas. We estimate that UGS facilities in the United States (U.S.) can store 327 TWh (9.8 MMT) of pure hydrogen. A complete transition to hydrogen storage would reduce the collective working‐gas energy of UGS facilities by ∼75%; however, most (73.2%) UGS facilities could maintain current energy demand using a 20% hydrogen‐natural gas blend. U.S. UGS facilities can buffer 23.9%–44.6% of the high and low hydrogen demand projected for 2050, respectively, which exceeds the current percentage of natural gas demand buffered by storage. Thus, transitioning UGS infrastructure to hydrogen could substantially reduce the number of new hydrogen storage facilities needed to support a hydrogen economy. Plain Language Summary: Hydrogen is a high energy content fuel that can be produced with low or zero greenhouse gas emissions from water and other chemicals. Creating hydrogen during periods of energy surplus and storing it underground is one long‐duration, low‐emission, energy storage option that can balance supply and demand for an entire electric grid. In the United States (U.S.), existing underground gas storage (UGS) facilities are a logical first place to consider subsurface hydrogen storage, because their geology has proven favorable for storing natural gas. We estimated that existing UGS facilities can store 327 TW‐h (9.8 million metric tons) of pure hydrogen. Transitioning from natural gas to pure hydrogen storage would reduce the total energy stored in existing UGS facilities by ∼75%. Storing hydrogen‐natural gas mixtures also reduces energy storage potential, but most (73.2%) UGS facilities can meet current energy demands with a 20% hydrogen blend. U.S. UGS facilities can store 23.9%–44.6% of the projected high and low hydrogen demand for 2050, respectively, suggesting that a partial transition of UGS infrastructure could reduce the need for new hydrogen storage facilities. These findings motivate research that explores the technical feasibility of underground hydrogen storage in natural gas storage reservoirs. Key Points: The total hydrogen working‐gas energy of underground gas storage facilities in the United States is estimated to be 327 TW‐hours Most (73.2%) underground gas storage facilities can store hydrogen blends up to 20% and continue to meet their current energy demand Hydrogen storage in existing underground gas storage facilities can sufficiently buffer the hydrogen demand projected for 2050