Techno-Economic Assessment of a Flexible Nuclear Power Plant Coupled with a Thermal Energy Storage Unit

Abstract

Nuclear power is a carbon-neutral energy source crucial for mitigating climate change effects. However, nuclear power plants (NPPs) often struggle to adapt efficiently to dynamic grid demands through load-following, presenting significant challenges. This study investigates the integration of Thermal Energy Storage (TES) systems with NPPs as a promising solution. By storing excess energy as heat, TES systems minimize the need for frequent energy conversions, enhancing the operational efficiency and economic viability of NPPs. Specifically, TES systems enhance the flexibility of NPPs to manage fluctuating grid demands, which could increase their profitability and return on investment. Our research centers on the Barakah NPP in the UAE, conducting a comprehensive thermo-economic analysis of an APR1400 NPP integrated with a TES unit. The study assesses various techno-economic benefits aspects, including the Levelized Cost of Electricity (LCOE), , and potential revenue from storing energy during off-peak hours and releasing it during peak demand. While the UAE has a regulated market where such practices are currently not permitted, our study assumes a future market shift to explore these possibilities.

Incorporating results from operational simulations, where we derate 10% of the NPP capacity during off-peak hours, our findings suggest that the total investment required for the TES system ranges between $195.8 million and $262.9 million, depending on the storage cycle duration. The LCOE is influenced by the storage duration: it is $83.5 per MWh for a 6-hour cycle, $79.7 per MWh for a 7-hour cycle, and $74.7 per MWh for a 9-hour cycle, calculated at a 10% discount rate over a 30-year lifespan. The profitability analysis indicates a potential maximum revenue of $624 million, assuming a 7% discount rate and a 40-year lifespan. Under more realistic assumptions— a 30-year lifespan and 10% discount—the projected revenue stands at $215.5 million.

The research contemplates the implications of the UAE's currently regulated electricity market on the economic feasibility of TES systems. We anticipate a shift towards market deregulation and model scenarios accordingly. If the market remains unchanged, we explore the benefits of using the specified 50 MWe capacity for desalination that can’t be sold under the existing power purchase agreement constraints. Given the country's arid conditions and limited freshwater resources, our analysis assesses the potential of utilizing 50 MWe of otherwise unused energy for desalination, based on a DEEP software evaluation. The proposed reverse osmosis (RO) plant is expected to produce approximately 297,000 cubic meters of water daily with a competitive Levelized Cost of Water (LCOW) of $0.76 per cubic meter, with an estimated NPV of $1.991 billion over a 20-year period, offering a substantial return and demonstrating significant financial viability.

Date of Award	18 Jul 2024
Original language	American English
Supervisor	Ahmed Alkaabi (Supervisor)