| Title | Evaluating geothermal-derived mineral production for sodium-ion batteries for utility scale energy storage in New Zealand |
|---|---|
| Authors | K. Titus, M. Ricketts, J. Haas, D. Dempsey, R. Peer, R. Archer |
| Year | 2025 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Sodium-ion batteries, minerals, future geothermal, energy storage, energy security |
| Abstract | Deriving minerals such as lithium from geothermal brine has garnered notable interest in recent years. Lithium is a critical component in batteries, and therefore increasingly valuable to the energy transition. Traditional deposits of lithium are locked to a handful of geographic locations. Thus, the production of lithium from geothermal brines can enable wider supply while generating additional revenues for geothermal operations. Sodium-ion batteries are an emerging counterpart to lithium-ion batteries, quickly approaching technological parity with lithium-ion batteries for utility scale storage. Given that the relative abundance of sodium in the Earth’s crust is three orders of magnitude larger than lithium, sodium-ion batteries can greatly improve scalability variable renewable energy technologies. This relative abundance is also reflected in the dissolved mineral concentrations of geothermal water, warranting further investigation. Here, we estimate the potential sodium-ion demand to supply utility scale battery storage for New Zealand by 2040. Further, we calculate the production potential of sodium-ions from New Zealand’s geothermal brines. A major advantage of geothermal-derived sodium-ions is the access to onsite energy from the geothermal plant. Due to the nature of metallic sodium, CO2 and ammonia are needed to facilitate the extraction. The former can be sourced directly from the geothermal fluid while the latter can be derived through a parasitic load. New Zealand’s utility scale battery demand is expected to grow up to 700 MWe by 2040. Assuming standard cycles of 4-hours per day and current energy densities of ~140 kWh/kg, this could require 528 kt of sodium. Our results show that Wairakei alone could supply this and provide enough electricity to facilitate all stages of cathode production. |