Frequently asked questions about utility-scale battery energy storage systems (BESS)

Utility-scale or grid-scale battery storage refers to technologies connected to the power grid that can store energy in rechargeable batteries and then supply it back to the grid. Without energy storage, electricity must be produced and consumed at exactly the same time. Energy storage systems allow electricity to be stored—and then discharged—at the most strategic and vital times, and locations. 

Battery energy storage systems can gather and store energy from either the grid directly or from an adjoining solar farm or other power source. The energy is stored in rechargeable batteries and then can be strategically deployed when needed most. The most commonly deployed form of energy storage today is lithium-ion battery storage, which leverages similar technology as your cell phones and laptops. In the case of battery energy storage systems, this is just on a much larger scale, with more extensive requirements for certification and safety.  

Learn more about how these systems store and deploy energy in BESS 101. 

Battery energy storage systems (BESS) come in many different shapes and sizes but are typically smaller than a 40’ shipping container. BESS containers, which hold the battery components, are set directly on concrete foundations and the ground area around them is covered in crushed rock, similar to a substation.  

Major components of a battery energy storage system are: 

Learn more about battery energy storage systems and how they work in: BESS 101 

Energy storage brings a number of benefits to customers, communities, and the grid: from maintaining a steady supply of clean energy to reinforcing our grid. Storage increases grid flexibility and helps provide uninterrupted power for consumers, businesses, and other users. These systems lower electricity costs while diversifying our energy mix for energy security and independence. 

Click here for a full overview of benefits.

Yes, energy storage systems are technology- and fuel-neutral. Battery systems can be charged by renewable energy sources, or can be charged directly from the grid. Electricity from the grid can be generated by any number of technologies, including renewables like solar as well as oil, natural gas, coal, and nuclear power. 

• Utility-scale battery energy storage systems (BESS) supports the integration of more, low cost renewable energy generation that is now the cheapest source of electricity worldwide. Along with affordable electricity, adding renewables to our energy mix increase our nation’s energy security. 

• BESS improves grid efficiency: Energy storage is instantly dispatchable to function both as generation and load, so it can help the grid adjust to fluctuations in demand and supply, which optimizes grid efficiency, alleviates transmission congestion, and increases grid flexibility. This reduces overall system costs. 

• BESS helps limit the need for costly energy imports and increases energy security: Energy storage improves energy security and maximizes the use of affordable electricity produced in the United States.

• BESS helps prevent and minimizes power outages: Energy storage can help prevent or reduce the risk of blackouts or brownouts by increasing peak power supply and by serving as backup power. 

Battery energy storage systems are beneficial for communities because of a whole range of indirect benefits they generate. They support energy independence by reducing local reliance on traditional fossil fuels and imported fuel sources to be reduced, and they also make the power grid more efficient and stable, protecting it from malfunctions or blackouts. Energy storage improves energy security and maximizes the use of low-cost, home-grown renewable electricity produced in the United States.