Synthetic Geothermal Reservoirs: Unlocking The Earth As An Infinite Battery

As an alternative to traditional geothermal energy production, this research evaluates the feasibility of utilizing a Synthetic Geothermal Reservoir (SGR) to store the abundant alternative energy resources such as solar, wind, nuclear, and industrial waste heat as thermal energy in the subsurface, and then to recover that heat as a 24/365 dispatchable geothermal reservoir for power or industrial heat. SGRs use the subsurface as a medium for thermal energy storage collected from various renewable sources such as wind energy or concentrated solar power to reliably produce on-demand industrial heat and electrical power, using the recovered heat. In this way, SGRs can provide weather-independent, renewable, baseload energy, without the traditional geothermal geographic constraints of initially hot rock. Instead, the hot geothermal reservoir is engineered by deploying petroleum workforce and other energy resources such as wind or solar. Results suggest SGR can turn off-peak power generation into baseload geothermal industrial heat or power, which can provide a unique way to “Drill to a Green Energy Future”. In the many sedimentary basins located around the globe, a technically producible geothermal resource will exist if there is sufficient sedimentary thickness. These resources are often low enthalpy that would be best suited for direct use applications. Organic Rankine Cycles may be able to generate electricity in some of these areas if there are sufficient water production rates. However, this is considered a niche power potential market as often the resource temperatures or fluid production are major limitations to profitable project. Here, we focus on the renewable energy penetration potential across different markets using SGR instead of traditional geothermal energy production. One example where SGR can be developed to broaden and enhance low-carbon energy production is in Wyoming, USA. Wyoming’s wind resource is cross examined with potential SGR locations and the change in wind utilization is calculated. California, USA, and the UK have energy markets with an abundance of wind or solar power curtailment. SGR can reduce curtailment by storing excess energy for later peak usage. The value proposition of SGR deployment includes producing cost-effective electric generation at the grid level as a zero-carbon baseload power supply. As a fully dispatchable renewable energy, SGR provides a stable and reliable capacity and reduces the grid cost for batteries. This study presents documented locations ideal for an SGR pilot project in Wyoming, in addition to high-level examinations of other markets with existing renewable energy curtailment. Successful SGR deployment will increase renewable energy penetration, which could then attract additional funding and investment driven by a clean energy grid.