Research institutions, nuclear technology developers and vendors, and utilities have expressed interest in transforming how nuclear energy is used by optimizing energy use through novel systems integration and process design. Such applications would expand the uses of nuclear energy beyond the electrical grid to produce nonelectrical energy services and products. These "integrated" or "hybrid" applications overcome the technical, economic, and institutional barriers that inhibit wider use of nuclear energy in coordinated energy systems, both centralized and distributed, particularly as rapid build-out of renewable technologies results in high variability in net electricity demand that must then be met by traditional dispatchable generation. Demonstration of nuclear energy use and conversion into nonelectrical energy intermediates and products (gases, minerals, refined metals, chemicals/chemical feedstocks, fresh water, etc.) will be a key focus of Integrated Energy Systems.
Integrated energy systems encompass both coordinated and tightly coupled energy system designs. In a coordinated energy system multiple energy generators may interact within a grid balancing area, involving loosely coupled electrical, thermal, and chemical networks, as well as various scales of energy storage, to provide reliable, sustainable, and affordable energy to a variety of energy users. A tightly coupled energy system involves co-design and co-control of multiple energy generators and energy users that are directly integrated via thermal, electrical, chemical means, which may include various forms of energy storage, working together to provide the lowest cost electricity to the grid while also supporting production of other commodities.
INL has been evaluating IES for a number of years via the DOE Office of Nuclear Energy Integrated Energy Systems Program (formerly Nuclear-Renewable Hybrid Energy Systems). INL researchers have developed and continue to enhance analysis tools to optimize the design and operation of candidate IES configurations – see System Simulation for more information and related reports. The lab has also developed nonnuclear, electrically heated test and demonstration facilities to support IES development. These facilities are summarized in Experimental Systems, with many new subsystems coming online in 2020.
As advanced reactor technologies come into the marketplace (e.g., high temperature reactors), even more opportunities will arise for integrating these innovative energy systems into new or existing industrial infrastructure. The IES program activities have been coordinated with DOE's Energy Efficiency and Renewable Energy (EERE) Fuel Cell Technologies Office (FCTO) since ~2014, with formal cost-share activities since 2018. Additional collaboration with DOE's Office of Fossil Energy (FE) was initiated in 2019. Demonstration activities related to the current fleet of light water reactors are managed by the DOE-NE LWRS Program Flexible Plant Operations & Generation Pathway.
Evolution of the electrical grid, and a general trend to enhance adoption of clean, non-emitting energy generation and use across all energy sectors, will require more coordination of multiple energy generation sources across traditionally independent energy use sectors.
The Future of Energy: Integrated Hybrid Systems