Session: 09-02 Pumped Thermal Energy Storage

Paper Number: 104232

104232 - Performance Characterization of a Small-Scale Pumped Thermal Energy Storage System 

Long-duration, grid-scale energy storage technologies provide a potential pathway to enable full penetration of renewables on the electricity grid and still maintain grid reliability and security. Among these technologies, pumped thermal energy storage (PTES), which stores energy thermally using a heat pump and discharges that stored thermal energy with a heat engine when needed, is an advantageous solution with round trip efficiency, no geographical constraints, and modularity for various use cases. To support the technology development, a first-of-a-kind small scale demonstration facility of an air-based PTES has been designed, built, and tested with the objective of better understanding controls strategies and overall operation. The PTES demonstration facility operates on simple-recuperated cycles for charge and discharge mode with separate drivetrains for each mode and shared heat exchangers and storage systems. At a discharge mode rating of 5kW, this facility storages heat in a thermal oil at up to 350 C and cold in a water-glycol mixture down to -10 C. Full system performance characterization is described with steady state and transient data from both charge and discharge modes during start-up, shut down, steady state, and system balance. These data highlight the importance of transient control tuning, the influence of ambient effects, and challenges associate with first implementation of a technology.

Presenting Author: Natalie Smith Southwest Research Institute

Presenting Author Biography: Natalie Smith is a Group Leader in the Machinery Department at SwRI with 14-years of experience in turbomachinery. Her research experience includes aerodynamic design and testing of turbomachinery and advanced system analysis for programs related to power generation, aviation, oil & gas and energy storage. Dr. Smith earned a Ph.D. and M.S. in Aeronautics and Astronautics from Purdue University where she focused on axial compressor aerodynamics of aviation engines.

Authors:

Natalie R. Smith Southwest Research Institute
Joshua Just Southwest Research Institute
Jeremy Johnson Southwest Research Institute
Fernando Karg-Bulnes Southwest Research Institute