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What Is Energy Systems Integration?

Energy systems integration (ESI) is an approach to solving big energy challenges that explores ways for energy systems to work more efficiently on their own and with each other.

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ESI brings together the wide range of energy carriers—electricity, thermal sources, and fuels—with other infrastructures, such as water, transportation, and data networks. It's a holistic view of all energy systems we use today.

ESI is about tapping into the combined strength of these energy systems—from those that operate in individual homes and communities to those that span whole regions of the world—and maximizing the value of every unit of energy we use.

While most energy sources, delivery systems, and demand-response programs are treated as stand-alone technologies today, ESI examines how they can optimally work together as a system. By focusing on the optimization of energy systems across multiple pathways and scales, we can better understand how to increase reliability, reduce costs, and minimize environmental impacts of our energy systems.

One complex example is a system composed of a solar photovoltaic system; an electrolyzer, which generates hydrogen from electricity; a hydrogen storage system; a fuel cell vehicle, which runs on hydrogen; and a stationary fuel cell, which generates power from hydrogen. This system can be used to store solar electricity in the form of hydrogen, which can then be used to either fuel the car or produce electricity when it's needed, such as after sunset. Optimizing such a system to both power a home and fuel a vehicle is a typical ESI challenge.

NREL's Energy Systems Integration Facility (ESIF) was specifically built to address these issues, and NREL now has more than 700 researchers and engineers tackling these challenges.

Featured Publications

Energy Systems Integration: An Evolving Energy Paradigm

Energy Systems Integration: Innovative Solutions for an Integrated World

NREL: Energy Systems Integration is Bigger than "Just" Renewables

Energy Systems Integration: A Convergence of Ideas


Juan Torres

Associate Lab Director, Energy Systems Integration | 303-275-3094