12Over the last decade, there has been a growing interest in large-scale use of hydrogen in the transportation and 13 renewable energy sectors. Relatively cost-effective storage options at scale are essential to realize the full potential 14 of hydrogen as an energy carrier. Underground geologic storage of hydrogen could offer substantial storage cost 15 reductions as well as buffer capacity to meet possible disruptions in supply or changing seasonal demands. Several 16 geologic storage site options are being considered including salt caverns, depleted oil and/or gas reservoirs, aquifers, 17and hard rock caverns. This paper describes an economic analysis that addresses the costs entailed in developing 18and operating a geologic storage facility. The analysis focuses on salt caverns to illustrate potential city demand for 19 hydrogen using geostorage options because (1) salt caverns are known to successfully contain hydrogen, and (2) 20 there is more geotechnical certainty involved with salt storage as compared to the other three storage options. The 21 main findings illustrate that geologic limitations rather than city demand cause a larger disparity between costs from 22 one city to the next. For example Detroit hydrogen storage within salt caverns will cost approximately three times 23 more than Los Angeles with its larger population. Detroit is located near thinly bedded salt formations, whereas Los 24Angeles has access to more massive salt formations. Los Angeles requires the development of larger and fewer 25 caverns and therefore has lower costs. 26 27

No abstract

In many regions across the nation geologic formations are currently being used to store natural gas underground. Storage options are dictated by the regional geology and the operational need. The U.S. Department of Energy (DOE) has an interest in understanding theses various geologic storage options, the advantages and disadvantages, in the hopes of developing an underground facility for the storage of hydrogen as a low cost storage option, as part of the hydrogen delivery infrastructure.Currently, depleted gas/oil reservoirs, aquifers, and salt caverns are the three main types of underground natural gas storage in use today. The other storage options available currently and in the near future, such as abandoned coal mines, lined hard rock caverns, and refrigerated mined caverns, will become more popular as the demand for natural gas storage grows, especially in regions were depleted reservoirs, aquifers, and salt deposits are not available.The storage of hydrogen within the same type of facilities, currently used for natural gas, may add new operational challenges to the existing cavern storage industry, such as the loss of hydrogen through chemical reactions and the occurrence of hydrogen embrittlement. Currently there are only three locations worldwide, two of which are in the United States, which store hydrogen. All three sites store hydrogen within salt caverns.

No abstract

Large scale geostorage options for fuels including natural gas and petroleum offer substantial buffer capacity to meet or hedge against supply disruptions. This same notion may be applied to large scale hydrogen storage to meet industrial or transportation sector needs. This study develops an assessment tool to calculate the potential 'gate-to-gate' life cycle costs for large scale hydrogen geostorage options in salt caverns, and continues to develop modules for depleted oil/gas reservoirs and aquifers. The U.S. Department of Energy has an interest in these types of storage to assess the geological, geomechanical and economic viability for this type of hydrogen storage. Understanding, and looking to quantify, the value of large-scale storage in a larger hydrogen supply and demand infrastructure may prove extremely beneficial for larger infrastructure modeling efforts when looking to identify the most efficient means to fuel a hydrogen demand (e.g., industrial or transportation-centric demand). Drawing from the knowledge gained in the underground large scale storage options for natural gas and petroleum in the U.S., the potential to store relatively large volumes of CO 2 in geological formations, the hydrogen storage assessment modeling will continue to build on these strengths while maintaining modeling transparency such that other modeling efforts may draw from this project.