Session: 10-04: Alternative Energy Conversion Technology (including Wind, Geothermal, Hydro, and Ocean)

Paper Number: 147544

147544 - Evaluating Required Capacities for Renewable Energy Technologies and the Needs of Seasonal Storage Towards 100% Decarbonization 

Abstract: 

In this study, a model is introduced to estimate the required installed generation capacity for a specified renewable energy source, combined with an energy storage system with a given capacity, to meet the energy demand if the system fully depends on this type of renewable energy. Additionally, the model calculates the average time span for different energy levels in the storage system and quantifies the distribution of energy storage capacity across different time spans to show the needs for short-term and long-term storage. The 2022 California power grid was used as a case study. Photovoltaic (PV), wind, geothermal and concentrated solar power (CSP) were chosen as the potential energy sources for analysis. Results indicated that the requirement for installed generation capacity decreased with an increase in energy storage capacity until it reached a minimum. Photovoltaic and concentrated solar power were found incapable of meeting the energy demand without an energy storage system due to their dependence on solar irradiance. Overall, a system with geothermal energy as the energy supply had the lowest requirement of installed capacity across all storage system capacity in comparison to the other three renewable sources evaluated. It was shown that, when an energy storage capacity increased from 0 GWh to 20,709 GWh, the required installed capacity could be reduced from 69.6GW to 32GW, which is much less than the 2022 California’s in-state installed capacity of 84.6GW, by assuming 100% round-trip efficiency (RTE). A decrease in RTE would lead to an increase in installed capacity. Furthermore, the average time span analysis revealed that for all types of energy sources assessed with different combinations of generation capacity and energy storage capacity, there is at least 12% of the energy storage capacity that has an average time span over a month. Systems utilizing wind or geothermal energy have a greater demand for long-term energy storage, with at least 54% or 46% of their energy storage capacity, respectively, having an average time span over a month. These findings suggest that long-term energy storage is essential in systems fully relying on a renewable energy source (PV, Wind, Geothermal or CSP) coupled with an energy storage system. This analysis of renewable energy and energy storage systems, using California power grid as a case study, not only sheds light on current capabilities and limitations of the analyzed renewable energy technologies but also provides foundation for future research and development efforts aimed at achieving a fully sustainable and reliable energy grid.

Presenting Author: Yu Zhou National Renewable Energy Laboratory

Presenting Author Biography: Yu Zhou is a post graduate intern in the Thermal Energy Systems group at NREL, holding a MS degree in Mechanical Engineering with a concentration in Thermofluids at Northeastern University and BS degree in Mechanical Engineering at University of New Hampshire. Her MS degree thesis was on requirement for seasonal energy storage with only solar and wind as energy sources, which is being furthered at NREL. Beside the research on seasonal energy storage topic, she is also working on the HelioCon project. Under the HelioCon project, Yu is helping with building the HelioCon Database and the scoping study on optical metrology tools for heliostat evaluation.

Authors:

Yu Zhou National Renewable Energy Laboratory
Guangdong Zhu National Renewable Energy Laboratory
Hameed Metghalchi Northeastern University