Nuclear Power, Photovoltaics, and Compressed Air Energy Storage: A Low-Cost, on-Demand Power Hub for Saudi Arabia

Abstract

Saudi Arabia’s energy portfolio is shifting toward low-carbon solar photovoltaics (PV) and nuclear energy. PV intermittency and seasonality must be considered along its low cost which reached globally low value of \(\text{c}\!\!| 1.04/kWh_{e,PV}\) in SA. Nuclear power plants, NPPs, are reliable and cost stable: \(\text{c}\!\!| 4.2 - 7.1/kWh_{e,NPP}\). NPP requires \(2.7{\text{liter}}/kWh_{e,NPP}\) freshwater for evaporative cooling stressing water resources. NPP is best operated at constant maximum power avoiding xenon poisoning operational complexity and keeping capital intensive LCOE low. This paper explores alternative roles for NPPs in Saudi Arabia: base-load electricity generation, dedicated desalination, and functioning as energy hub integrating energy storage systems and PV power. Base-load operation is not competitive compared to combined cycle gas turbine (CCGT) or future PV/battery systems. NPP can operate thermal and membrane desalination with good economics of \(293.7{\text{liter}}/kWh_{e}\) and energy cost component of \(\$ 0.14 - 0.24/m^{3} .\). Our study recommends integrating constant NPPs with intermittent PV systems using compressed air energy storage (CAES). Liquid piston used in CAES enables efficient quasi-isothermal compression/expansion. PV powers charging/compression and NPP heat powers discharging/expansion. The system includes ice thermal storage, 310 °C phase-changing-material hot storage with 200 bar high-pressure tanks storing cold air. The system enables power on demand, POD independent from PV and NPP time profiles. PV-NPP-CAES POD costs 36% less than NPP cost. Electricity generated is 2.35X higher than its NPP contribution. Integrating SA locally advantageous PV to reliable NPPs by utilizing industrially mature CAES and thermal storage represents a promising energy plan for Saudi Arabia, constituting an energy hub of low-cost and reliable power on demand.