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Energy reliability is the ability of a power system to withstand instability, uncontrolled events, cascading failures, or unanticipated loss of system components. Put another way, it means being able to consistently depend on power delivery to homes, buildings, and devices, even in the face of physical and cyber events that cause power disruptions.

Energy reliability is critical to Americans’ daily lives. It is vital to human health, safety, and well-being and the nation’s economic prosperity and security. Reliable energy keeps life-saving hospital equipment and communications systems operating, buildings at safe temperatures with good ventilation, and much more. The effects of climate change and aging U.S. energy infrastructure are key challenges to energy reliability.

What Makes Energy Reliable

Reliable energy is the result of energy infrastructure that can withstand and quickly recover from typical disruptions. Energy reliability can be particularly challenging for remote, rural, and island communities, as well as for low-income communities, which historically have received lower investments in energy infrastructure. Reasons that reliable energy is challenging in these communities include limited access to centralized energy systems and difficulty paying electricity bills due to a disproportionately high energy burden, or the percentage of household income spent on energy costs. Learn about low-income community energy solutions

Renewable energy contributes to energy reliability because there are no limits to the amount of wind, solar, water, and geothermal power that Earth provides. Renewable energy generates about 20% of U.S. electricity, and that amount is growing. The U.S. Department of Energy funds research and development of technologies to leverage these resources at low cost to achieve a 100% clean electricity sector by 2035. Energy storage technologies can ensure energy reliability by storing renewable energy for use whenever it is needed, such as during a power outage. Energy efficiency also supports energy reliability by helping ensure energy use and the electricity grid are well managed.

Energy Reliability News

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An installment in EERE’s Clean Energy in Action series, this video highlights EERE’s work to test and prove enhanced geothermal systems (EGS) technologies at Utah FORGE.

Energy Storage Improves Energy Reliability

Various technologies enable energy to be harnessed and stored for later use. Pumped storage hydropower is responsible for most U.S. commercial energy storage capacity and has been used for more than 100 years. Wind and solar energy can be captured and stored for later use with batteries, and researchers are investigating geothermal energy storage.

Energy storage is also essential to clean transportation. To ensure on- and off-road vehicles reliably move people and goods from one place to another, EERE invests in research and development of hydrogen storage and batteries.

The U.S. Department of Energy's Energy Storage Grand Challenge is a comprehensive program to accelerate the development, commercialization, and use of next-generation energy storage technologies. As part of this program, the Long Duration Storage Shot aims to reduce the cost of grid-scale energy storage by 90% for systems that deliver at least 10 hours of duration within the decade.