Hybrid Energy System

- Overview 

Hybrid energy systems combining nuclear and renewable energy can help significantly reduce greenhouse gas (GHG) emissions. Hybrid systems could also facilitate combined heat and power for desalination, hydrogen production, district heating, cooling and other industrial applications. 

Future energy systems must meet not only stricter greenhouse gas emission requirements, but also other pollutants such as sulfur oxides, nitrogen oxides, mercury, heavy metals, and particulate matter. Nuclear power can meet these stringent requirements and is competitive. 

In addition, nuclear power plants can contribute to electricity security in a number of ways, including by maintaining grid stability and complementing decarbonization strategies, as nuclear power plants can adjust generation in part to changes in demand and supply. 

As the share of variable renewable energy sources such as wind and solar photovoltaics (PV) rises, the demand for such services will increase.

- Flexible Operation of Renewable Energy

Nuclear energy can generate large amounts of reliable, carbon-free electricity. It works day and night at any time of the year. This stability is why nuclear power is often used as base load - continuous operation with little (if any) variation in output. 

However, some nuclear power plants now contribute to grid stability by supporting intermittent output of renewable energy through flexible operation or load following (adjusting output according to fluctuations in electricity demand).

As intermittent renewable energy systems (mainly solar and wind) increase their share of the grid, there is a need for more flexible power generation. This can take many forms: hydroelectric, gas-fired power plants, advanced batteries or nuclear. In France and Germany, nuclear power load following has been a reality for many years.

- SMR as Part of a Hybrid System

There are around 50 small, medium or modular reactor (SMR) concepts in various stages of development around the world, and SMRs can also play an important role in hybrid energy systems.

They have the potential to meet the needs of a wide range of users and serve as a low-carbon alternative to aging fossil fuel power plants. They also have enhanced safety features and are suitable for non-electric applications such as heating and desalination. Featuring advanced engineering capabilities, SMRs are designed to be factory built and shipped to utilities for installation, and can be deployed as single or multi-module plants.

SMRs are ready to complete the energy system as they add flexibility and can be easily integrated into systems dominated by renewable energy. Additionally, NuScale plants (NuScale Power, a SMR technology company) are ideally suited to provide carbon-free heat and energy for a variety of industrial applications, such as hydrogen production for clean fuels and desalination for clean water production.

SMRs can also play a stabilizing role in grids with a high share of renewable energy and help reduce the overall cost of a low-carbon energy system. This combination is expected to reduce rate fluctuations and system costs for grid management and development.

[Hybrid Energy System - IAEA]

- Cogeneration: Non-electric Applications

Nuclear power plants generate large amounts of heat, which can either be converted into electricity or used directly for other energy uses. Cogeneration combines the production of usable heat and electricity into one system, which can drastically reduce carbon emissions and increase overall efficiency. 

This is a more efficient use of the fuel, as waste heat from electricity generation is used productively for district heating, desalination or hydrogen production for the decarbonisation of a range of industries including steel manufacturing and transport. 

Demand for hydrogen has tripled since 1975, while the industry is almost entirely supplied by fossil fuels. Especially as more hydrogen-powered fuel cell cars and trains enter the market, small and medium-sized reactors have the potential to displace fossil fuel power plants, which emit around 830 million tons of CO2 per year through hydrogen production alone. 

Despite extensive experience in nuclear desalination, the high temperature and operational flexibility of SMRs could place them at the heart of a growing hydrogen market. This hybrid energy system could potentially be designed for other non-electric, energy-intensive applications, including: chemical feedstock for fertilizers, polymers, plastics, and textiles; drinking water for sea and brine desalination; and carbon dioxide for enhanced oil recovery Or as a heat transfer medium. Incorporating such products can maximize the overall performance and profitability of energy systems.