Session: 03-03: Energy Storage Separate from CSP: Thermal, Mechanical, Thermochemical

Paper Number: 141557

141557 - Repurposing Abandoned Wells for Energy Storage 

Abstract: 

The success of the energy transition relies on the economic efficiency of the newly established clean energy projects for storage to address intermittent energy generation from renewable resources. However, the high initial investment of some classes of projects can significantly impede their further development - compressed air energy storage (CAES) is one such case in point. One possible solution to increase economic efficiency is to leverage some pre-existing infrastructure for renewable energy storage. The objective of this research is to explore the feasibility of integrating the numerous abandoned oil and gas wells (AOGWs) in the United States into CAES development. Such subsurface wells open the possibility to dual use of their natural geothermal heat to increase the system efficiency.

The need for excessive initial investment significantly impedes the development of compressed air energy storage (CAES) projects. However, the reuse of cased and abandoned oil and gas wells (AOGWs) as containment cells for pressurized air obviates this problem and alleviates the many environmental issues caused by AOGWs. We propose a novel concept of geothermal-assisted (GA) adiabatic compressed air energy storage (GA-CAES) which integrates abundant AOGWs and ubiquitous deep geothermal heat into a single seamless CAES system. The hot reservoir heats the air charge within the CAES and increases system efficiency. The performance of GA-CAES using AOGWs is investigated through numerical simulations with the model validated against observations from a reference study. According to the simulation results, the utilization of subsurface geothermal heat increases system efficiency. The application of AOGWs with geothermal heat transfer increases the compressed air temperature by ~45 K. Concurrently, the increase in temperature further pressurizes the air in the well by ~0.5 MPa during a single compression cycle. The input of geothermal energy increases the system round-trip efficiency by ~4% - a considerable benefit. This improvement in efficiency, coupled with the significant cost saving in the beneficial reuse of AOGWs significantly decreases the initial investment for such projects and increases system efficiency. The project payback period can be shortened by ~1 year over the usual ~3 years without the benefit of AOGWs. This novel arrangement can achieve cleaner, more profitable and more efficient CAES systems that are thus of greater viability. This study proposes then qualifies a novel method capable of boosting the efficiency of CAES and lowering the investment risk for future CAES projects – and hence elevating viability as a contributing solution to the penetration of renewables into the marketplace as a dispatchable resource. 

Presenting Author: Arash Dahi Taleghani Pennsylvania State University

Presenting Author Biography: Dr. Arash Dahi Taleghani currently serves as a Professor in the John and Willie Leone Family Department of Energy and Mineral Engineering. Dr Dahi’s research interests lie broadly at the intersection of geomechanics and material science with emphasis on subsurface energy systems, i.e. innovation in cementing/sealing materials, energy storage, and geothermal systems. He holds B.S. and M.S. degrees in Civil Engineering from Sharif University, Iran in 2001, and a Ph.D. degree in Engineering from the University of Texas at Austin in 2009.

Authors:

Arash Dahi Taleghani Pennsylvania State University