Increasing Revenue of Nuclear Power Plants With Thermal Storage

Abstract

Introducing large amounts of electricity produced from variable renewable energy sources such as wind and solar decreases wholesale electricity price while increasing the volatility of the market. These conditions drive the need for peak-load power generation, while regulation requirements fuel the push for flexible power generation. The increase of variable renewable energy in the market share, along with falling natural gas prices, makes nuclear power plants less competitive. Thermal storage is being considered to increase the nuclear power plant revenue. Thermal storage increases the flexibility of the nuclear plant system without sacrificing its efficiency. There are multiple opportunities to increase the nuclear power plant revenue, including increased capacity payments, arbitrage, and ancillary services. An economic analysis was performed to investigate the revenue increase of the system with thermal storage. The investment cost was assessed, and net present value was evaluated for the considered scenarios. Two system designs were considered in the analysis: a thermal storage system using the existing power conversion infrastructure and an integrated design with thermal storage fully incorporated into the reactor system design. The preliminary analysis showed that introducing a thermal storage system is profitable for some scenarios considered. Profitability depends significantly on the storage size, output flexibility, share of variable renewable energy, and market characteristics.

Molten salts: Potential candidates for thermal energy storage applications

“…We can further acknowledge the architecture and purpose of two types of molten salt ESS designs for nuclear‐TES: the thermocline system and the two‐tank direct ESS 126 . The former is found to be more economically efficient due to the inexpensive choice of salts (KCl‐MgCl 2 ), 127 while the latter is found to be more thermally efficient due to the power cycles involved and the high volumetric heat capacity of the salts involved (LiF‐NaF‐KF) 128 . Following below is a review of their architectures and working.…”

“…126 The former is found to be more economically efficient due to the inexpensive choice of salts (KCl-MgCl 2 ), 127 while the latter is found to be more thermally efficient due to the power cycles involved and the high volumetric heat capacity of the salts involved (LiF-NaF-KF). 128 Following below is a review of their architectures and working.…”

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

“…High penetration of renewables is posing challenges for operation of conventional NPPs in a grid integrated with fast varying renewables and uncertainty due to limited accuracy in forecasting. The flexible operation of NPPs is popular in some countries such as Germany, France, Belgium, etc., thereby proving the capability of the nuclear technology to be quite flexible [7,10,11]. Flexibility for conventional NPPs without cycling can only be achieved through auxiliary power installations that can be tightly integrated with NPPs, provide adequate response for flexibility, and can allow coordinated control enabling the flexibility.…”

Nuclear Power Coupled With Thermal Energy Storage: Impact of Technical Performance on Economics in an Exemplary Electricity Grid

“…They estimated that storage would increase the capacity factor of a nuclear power plant by 2.5% with a renewable penetration of 60% and discharge power equal to 110% of the nominal baseload. Borowiec et al [24] considered TES to increase the revenue of nuclear power plants in US electricity markets through capacity payments, arbitrage, and ancillary services.…”