Frequently Asked Questions

Have questions? We’ve compiled answers to some of the most common questions below, but if you have others, don’t hesitate to contact us at energystorage@nyserda.ny.gov.

How does energy storage work?

What is energy storage?
Energy storage provides the opportunity for a homeowner to store excess or less expensive electricity on site to be used at a later time. There are various forms of energy storage, however, lithium-ion batteries currently provide most home backup power systems.

What does an energy storage battery look like?
Battery systems typically look like a box mounted on a wall or a small cabinet mounted outside your home. The units are self-contained and operate without homeowner intervention. The system should be monitored remotely from a central station provided by the installer through an internet or cell connection to alert you if anything requires maintenance.

Where can an energy storage battery be placed?
Almost all energy storage systems are placed near the home’s circuit breaker panel, on the wall of a garage, attached to the house, or on a pad near the house.

How big will my energy storage system be, and how is that decided?
Storage systems have a small footprint and are the size of a small cabinet. Its size will depend on your electric usage and the number of loads you want to power during a grid outage. Energy storage systems are measured in kilowatt hours (kWh) and a typical system size is around 10-20 kWh. Your contractor will determine which circuits or appliances you want to backup during a grid outage, what their electric usage would be, and will calculate the storage capacity accordingly. For reference, a 100-watt light bulb operating for 1 hour uses 100 watt hours of electricity.  After 10 hours, the bulb uses 1,000 watts (1 kilowatt hour) of electricity.

Is battery energy storage safe?
Lithium-ion systems are the most common forms of residential storage backup power, with tens of thousands of systems deployed. This is the same underlying battery technology in your cell phone or electric vehicle but includes multiple levels of monitoring and system protections built into system design. As with any electrical or fuel-based device or appliance, safety risk cannot be mitigated to zero. Electrical and fire codes and industry standards dictate the minimum requirements that must be met. Any installation that receives NYSERDA incentives must meet the requirements in NYSERDA’s Battery Energy Storage Guidebook which include the most recent Underwriter Lab safety listings and requirements of the 2021 Fire Code.

What is islanding?
Islanding is when your home operates independently from the electric grid for a period of time. When energy storage and solar are paired, your house will still be connected to the electric grid during everyday operation. However, if the electric grid goes out because of a disruption during a weather event, those circuits that are powered by your backup energy storage system will continue without any interruption. The combination of your solar system, energy storage system, and inverter will power your critical circuits safely and without any noise or emissions.

What are the benefits of pairing energy storage and solar?

Why pair energy storage with solar, and what are the benefits?
When you have an excess of solar energy it can be more beneficial to store it for later use rather than selling it back to the grid. You can also benefit from federal tax credits by installing energy storage with solar which can reduce the cost of the storage system by up to 30%. Energy storage also provides backup power for specific loads or appliances in your home during an electric grid outage.

What are the grid benefits and why should I care about those benefits?
The electric grid is built to accommodate the busiest most congested time of the year. This means that the entire electric generation and delivery infrastructure is sized to meet the single highest demand period during the year. Most times of the year, the electric usage is half of this level. As more and more customers install solar and energy storage on site, it means in time the utility can start to reduce the size of the delivery and generating infrastructure, saving everyone money. It also reduces the need for the most polluting power plants to meet these periods of peak electric demand. Your energy storage system will help maximize the benefits of clean energy by reducing your reliance on the electric grid during the busiest times.

What is a utility load relief program, and how can I join?
Utility load relief programs pay you to reduce the electricity you’re drawing from the electric grid during the highest demand days, which typically occur over a small number of hot summer days. Your energy storage system charges when excess electricity is available and then reduces the amount of electricity you pull from the electric utility during these high demand hours by discharging the storage system. Not all utilities offer residential load relief programs, please check with your utility for more information. In Long Island, LIPA’s Dynamic Load Management tariff [PDF]Link opens in new window - close new window to return to this page. provides payments for up to 10 years for load reduction provided during demand response call periods.

What are time of use rates?
Time of use rates determine your electric charges based on when you consume electricity, rather than an average across all hours of the month. Because it’s more expensive to use electricity during the peak periods of the day when electric demand is highest, you save money by using the stored electricity from the energy storage system during those times instead of drawing from the grid. Learn more about residential time of use rates on Long IslandLink opens in new window - close new window to return to this page..

How can I use energy storage in my home?

How can I use energy storage in my home and what are the benefits?
Energy storage can provide you with backup power during a grid outage. It won’t power your entire house, but it can power critical functions like heat, refrigeration, and lighting without the need for a backup generator. Additionally, using energy storage in your home can help you save on your electric bills if you enroll in a utility load relief program or switch to a time of use rate.

If the power goes out, will my energy storage system power my entire home?
No, a battery storage system will not power your entire home. Very similar to a backup generator that runs on gas, you determine how many appliances you want to power in your home. Your contractor will help you determine which circuits in your home should be powered. These will likely include a furnace, refrigerator, lighting, and some kitchen circuits – enough so that you could comfortably live in your home during an extended electric grid outage after a major storm. The storage will need to recharge from the solar system during an outage and your contractor will help size the two to best meet your needs.