Grid-Scale Ternary-Pumped Thermal Electricity Storage for Flexible Operation of Nuclear Power Generation under High Penetration of Renewable Energy Sources

• Published in: Energies (Basel) Vol. 14; no. 13; p. 3858
• Main Authors: Hovsapian, Rob, Osorio, Julian D., Panwar, Mayank, Chryssostomidis, Chryssostomos, Ordonez, Juan C.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-07-2021
• Subjects: Alternative energy sources; Cold storage; Consumption; Controllability; Dynamic loads; Electric energy storage; Electric power systems; Electrical loads; Electricity; Energy resources; Energy sources; Energy storage; Flexibility; flexible operation; grid integration; Heat distributing units; Heat engines; Heat exchangers; Heat pumps; Integration; Load distribution; Molten salts; Nuclear electric power generation; Nuclear energy; Nuclear power plants; nuclear reactor; Nuclear reactors; POWER TRANSMISSION AND DISTRIBUTION; Renewable energy sources; Renewable resources; Salts; Shutdowns; Storage tanks; t-PTES; ternary-pumped thermal electricity storage; ternary-Pumped Thermal Electricity Storage (t-PTES); Thermal cycling; Thermal energy; Thermal storage; thermal-electrical co-simulation; United States > US
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en14133858

In this work, the integration of a grid-scale ternary-Pumped Thermal Electricity Storage (t-PTES) with a nuclear power generation to enhance operation flexibility is assessed using physics-based models and digital real time simulation. A part of the electricity from the nuclear power generation is delivered to the grid, and the balance is used to power a heat pump that can be augmented by an auxiliary resistive load element to increase the charging rate of the thermal storage. This increases the thermal potential between hot and cold thermal stores (usually solid materials or molten salts inside large storage tanks). The thermal energy is transformed back into electricity by reversing the heat pump cycle. Different transient scenarios including startup, shutdown, and power change for grid-connected operation are simulated to determine the behavior of the hybrid nuclear-t-PTES system operating under variable loads that constitute a departure from conventional, baseload nuclear plant operation schemes. Ternary refers to the three modes operation: (i) heat pump (including heating coil), (ii) heat engine, and (iii) simultaneous operation of heat pump (including heating coil) and heat engine during changeover from pumping to generation or vice-versa. The controllability of t-PTES in the short timescales as a dynamic load is used to demonstrate operational flexibility of hybrid nuclear plants for flexible operation through advanced load management. The integration of t-PTES into nuclear power systems enhances the system flexibility and is an enabler for high penetration of renewable energy resources.