Cycle Considerations for the Conceptual Design of a Pumped Heat Energy Storage System
Grid-scale energy storage technologies that can provide greater than ten hours of electricity at full power address a critical need for full penetration of renewables on electricity grids worldwide. These technologies minimize renewable curtailment, while maximizing grid security and reliability. Other energy storage solutions such as pumped hydro and compressed air energy have been developed, but have geological and geographical constraints that limit their applications. Pumped Heat Electricity Storage (PHES) systems can store energy thermally in any location at the extremely low costs necessary for displacing fossil fuels, reducing foreign fuel imports, and reducing emissions to maintain the energy security of the United States.
A key parameter of interest for energy storage applications is the Round-Trip Efficiency (RTE), defined as the ratio between energy into the system to the energy retrieved. This paper discusses a conceptual cycle design of a recuperated PHES system, specifically examining the effects of turbomachinery and storage temperature on the overall cycle and RTE. Key challenges for cycle design include operating state points for the compressor and turbine that are significantly different from one another in charge mode and discharge mode. The decision to include one or two drivetrains effects turbomachinery performance, cycle optimization and overall cost. Initial design point machine sizing and machine selection for a small-scale demonstration system are also discussed.
Cycle Considerations for the Conceptual Design of a Pumped Heat Energy Storage System
Category
Technical Paper Publication
Description
Session: 44-04 Large-scale Thermal storage and Power-to-gas Energy Storage
ASME Paper Number: GT2020-15657
Start Time: September 21, 2020, 09:45 AM
Presenting Author: Natalie Smith
Authors: Brittany Tom Southwest Research Institute
Natalie Smith Southwest Research Institute
Aaron Mcclung Southwest Research Institute