Energy storage helps make renewables like wind and solar more practical and reliable on the grid. It can smooth out the variable output of intermittent resources and help with services like static reserve and regulation of frequency and voltage.
Battery systems are the most common form of energy storage, but there are other technologies in development as well — compressed air, superconducting magnets, and underground pumped hydro.
Costs
Energy storage helps lower electricity bills, maximize renewable energy usage, and enhance grid reliability. It can be deployed at a residential or utility-scale, and offers a range of applications from optimizing solar usage to managing peak loads and supplying backup power. As a result, it is one of the most cost-effective technologies for supporting renewable integration.
In addition to lowering electricity costs, energy storage can help avoid or minimize grid outages, which are costly and often dangerous to people and the environment. Energy storage is technology- and fuel-neutral, so it can complement any generation type, including conventional sources like natural gas and nuclear power.
Residential battery energy storage systems (BESS) use batteries—usually lithium-ion—to store and then supply power, either to the grid or as behind-the-meter, home energy management solutions. Upfront investment and maintenance costs vary, but homeowners can leverage available incentives to offset costs. For a deeper dive into cost considerations, the updated IRENA Cost-of-Service Tool provides a framework to assess different ESS configurations.
Benefits
Energy storage systems (ESS) decouple when electricity is created from when it is consumed, enabling the integration of renewable energy sources like wind and solar. This allows businesses to cut demand charges, shift consumption to lower-cost times, and provide critical backup power during grid supply disruptions.
Home energy storage systems allow homeowners to cut their utility bills and insulate themselves from price spikes. Commercial ESS systems can also lower electricity costs by reducing peak loads or participating in demand-side management programs.
ESSs with short durations can provide grid support services such as frequency regulation and voltage control, while those with long-duration can provide energy arbitrage and other value-added services. Pumped hydro and compressed air are examples of ESSs with long durations, while batteries and flywheels offer short-duration energy storage.
Increasingly, governments are pushing businesses to adopt renewable energy, but these energy sources are weather-dependent, making ESS essential for maintaining a stable power output. Battery storage systems can bridge the gap between intermittent renewable sources and traditional fossil fuels by storing power for use at night or on cloudy days, or by providing backup power during disruptions.
Grid Integration
Managing electricity networks effectively is vital to lower energy consumption and reduce the carbon intensity of the economy. Energy storage can help a variety of industrial enterprises achieve this goal by providing stable and reliable power supply and decreasing the operating costs of their production equipment.
Modernizing grids to adapt them to renewables requires the ability to fast track intermittent generation and smooth out variability. A smart energy system can do this, with monitoring and management systems reporting generation data from wind and solar farms or distributed photovoltaic installations, demand requirements from endpoints and power availability from traditional generator locations to ensure that utilities use the cleanest, cheapest power available at all times.
In addition, a smart grid can send information to consumers to switch off non-essential services during periods of surplus energy. This can further reduce the load on the grid and reduce transmission losses. Finally, effective grid integration across borders requires cooperation between nations to share infrastructure and develop shared market structures to avoid the risks of blackout spill overs and other transnational supply problems.
Reliability
Battery energy storage systems (BESS) strengthen grid reliability by responding to electricity demand fluctuations on sub-hourly timescales. They are also used to provide other front-of-the-meter services like voltage support, renewable integration and peak demand management.
BESS can be AC or DC coupled, depending on how they are connected to the grid or other equipment. DC coupled systems are often the best choice for solar generation, as they allow solar to be discharged directly into batteries without first needing a power conversion step.
Batteries degrade over their lifespan based on a variety of factors including the technology type, use case, and temperature. As they age, BESS systems are regulated through state-of-the-art Battery Management Systems which monitor performance and safety. These systems, along with thermal controls, and site infrastructure ensure that facilities operate safely as mandated by NFPA 855. Even in the rare event that fires occur, they do not pose a long-term threat to communities, as gases dissipate quickly and there is limited contamination of soil and waterways.