Hydrogen storage holds the potential to address the intermittency of renewables in the power sector as well as provide low-cost emissions-free energy. However, hydrogen (H2) as an energy carrier has a low density and low energy per unit volume at standard conditions. This significantly complicates large-scale storage using chemical and physical methods. Aquifers, salt caverns, and depleted/abandoned oil and gas fields are some of the subsurface options that can be used to store hydrogen underground because they possess the requisite volumes to store H2 at higher pressures. In this study, the recent interest in exploiting salt deposits in North Dakota as hydrogen storage sites is addressed. The Pine salt in the Spearfish Formation and the "A" salt in the Opeche Formation are the thickest and most prevalent of these salts, making them the most viable candidates for these types of ventures. We tested the feasibility of storing hydrogen by analyzing the behavior of the salts through geo-mechanical characterization. We estimated the mechanical properties of the rock salt from log data and considered the stresses of the salt formation to aid understanding and determine possible limitations. Geomechanical characterization showed a typical behavior of stresses, Sv>SH> Sh.
The intermittency of renewable energy resources has created an urgent need for energy storage. Deployment of energy storage options will accelerate flexibility in grid operations and provide energy that can be applied to a diverse portfolio of industries. It can also provide environmental benefits by improving the overall efficiency of the power grid and providing a basis for the broader adoption of renewable energy thus reducing harmful emissions to the atmosphere (Uliasz-Misiak et al., 2022). According to Tarkowski & Uliasz-Misiak (2022), H2 is a reliable energy carrier that can play an important role in decarbonizing our current energy system. Hydrogen storage can be used to supplement energy demands associated with seasonal heating needs and peak load (Laban, 2020). The challenge with hydrogen however is that it has a higher energy per unit mass than any other liquid fuel. As an energy carrier, H2 has a low density of 0.089 kg/m3 at standard conditions. As such, it is difficult to store large volumes using chemical and physical storage methods (Lord, 2014). Currently, H2 storage can be stored on a small scale as compressed gas at around 5076 – 13778 psi in type 2, 3 or 4 tanks. In order to store gas at such high pressures, the capital and operational expenditures are significant. On medium scale, it can be potentially stored as a gas in spherical vessels at low pressures of ∼290psi thus requiring larger volume (Papadias & Ahluwalia, 2021).
