Session: 04-01: Energy Storage Systems and Applications

Paper Number: 158471

158471 - Comparison of Different Solar to Electric Power Options for 24 Hours Continuous Power Supply 

Abstract: 

Solar energy is integral to achieving decarbonization in electricity production and industrial processes. However, its reliance on solar irradiance introduces challenges, particularly intermittency, which is more prone to cause grid instability due to mismatches between energy supply and demand. During periods of high irradiance, surplus energy is often generated, resulting in energy curtailment, while periods of low or no irradiance cause deficiencies in power generation. To address these challenges, storing excess solar energy is critical for enabling a consistent 24/7 power supply. Photovoltaic (PV) systems and solar thermal power plants represent the two primary pathways for solar energy utilization, both requiring energy storage technologies to store surplus energy for later use. PV systems, commonly coupled with batteries, dominate the market due to their simplicity and scalability. Meanwhile, solar thermal power plants frequently utilize molten salt tanks as their energy storage medium. Beyond these widely implemented methods, a variety of alternative storage and conversion technologies exist, each offering distinct efficiencies and feasibility levels. These include advanced batteries, hydrogen generation through water electrolysis, and innovative storage solutions such as pumped heat, pumped hydropower, compressed air, flywheels, and gravity systems. Thermal solar power plants also offer diverse opportunities for electricity generation through different heat transfer mediums and power blocks, such as Rankine cycles, supercritical CO₂, Helium Brayton cycles, and combined cycles like sCO₂-Isopentane and Air-ORC. Each configuration has unique advantages and trade-offs. However, comparisons of solar-to-electricity efficiencies are often complicated by inconsistent operational conditions, assumptions, and constraints. This variability underscores the need for a unified framework to enable fair and comprehensive evaluations. This study addresses this gap by analyzing 18 different solar energy utilization scenarios and evaluating their solar-to-electricity efficiencies under the same assumptions and conditions. Using a hypothetical scenario of 200 MW of solar irradiance input—100 MW for immediate electricity generation and 100 MW for energy storage—the study examines both PV and thermal solar pathways. Ten scenarios focus on PV-based configurations combined with various storage technologies, while eight scenarios explore thermal solar configurations with distinct power blocks and energy storage combinations. The results demonstrate significant differences in solar-to-electricity efficiencies across the scenarios, with thermal solar systems consistently outperforming PV-based systems under comparable conditions. These findings highlight the potential of thermal solar power plants, particularly when integrated with advanced storage technologies, to address the challenges of intermittency and curtailment. Furthermore, the study establishes a valuable benchmark for evaluating solar energy technologies, offering insights to guide future research and development efforts.

Presenting Author: Mazdak Gorji University of New Orleans

Presenting Author Biography: I am a graduate student conducting research at the Energy Conversion and Conservation Center (ECCC) in the University of New Orleans. My research is focused on the continuous utility-scale solar-only power generation and diverse available options for the energy storage.