Hydrogen (H2) molecules are the smallest molecules in the universe — one of many factors that present containment challenges for maintaining the integrity of underground H2 storage capabilities. NETL researchers are devoting special care and study to understanding how best to safely store H2 in cement-sealed underground geologic formations. The work is part of NETL’s participation in a multi-national laboratory effort known as Subsurface Hydrogen Assessment, Storage and Technology Acceleration (SHASTA). The Department of Energy’s (DOE) Office of Fossil Energy and Carbon Management established SHASTA in 2021 to explore H2 storage opportunities in geologic reservoirs. In addition to NETL, DOE labs participating in SHASTA include the Pacific Northwest National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratories.
Hydrogen is emerging as a low-carbon fuel option for transportation, electricity generation, manufacturing applications, and clean energy technologies that will accelerate the United States’ transition to a low-carbon economy if underground storage of H2 can be realized.
Large-scale storage of H2 can be achieved by using underground resources like how natural gas has been stored for the past century. Underground hydrogen storage has the potential to provide the storage capacity required for the future hydrogen energy market.
During the creation of underground storage facilities, a borehole is drilled and lined with steel casing, which is cemented in place. The primary materials of well construction include steel (carbon and/or stainless), polymer elastomers (polymers with elastic properties), and cement. It is important to understand how H2 storage operations can impact the integrity of each of these three materials.
The compatibility of H2 with steel and other metals has been documented in applications like nuclear waste storage. Research has also been conducted that identifies failure mechanisms in elastomers in downhole environments.