Energy storage provides an important service by helping balance electricity supply and demand to lower both costs and emissions. It’s especially beneficial in communities located far from the main power grid such as islands or microgrids.
Stores of energy include pumped hydro (lifting water), batteries (chemical reactions), thermal (heat storage) and flywheels; with each method offering different capacities and release times or duration.
1. Maintaining the Balance of Electricity Supply and Demand
Energy storage can help ensure the amount of energy produced satisfies demand in an electric grid system.
Battery energy storage can help balance supply and demand by charging up when there is more supply than demand and then discharging to restore equilibrium when demand exceeds supply.
Flexibility is critical in the integration of renewable energy sources while limiting pollution-emitting peaker plants. Energy Storage Systems (ESSs) provide efficient and dependable support to clean energy transition, and help ensure power outages during heat waves don’t disrupt communities or businesses.
2. Reducing High Demand
Energy storage enables utilities to shift electricity usage away from peak periods and towards lower-demand periods, smoothening out their demand curve and avoiding expensive price spikes for customers. As such, utilities save money and decrease grid stress levels, as well as decreasing emissions-intensive power plant construction needs.
Energy storage can help businesses and industries reduce demand charges on their electricity bills by helping reduce large peak loads during Time of Use rates, which typically have different volumetric charges per window of time throughout the day, week and year.
Energy storage systems offer additional services at reduced costs, such as frequency regulation and spinning reserve, that help keep lights on in homes, communities and businesses alike. This helps avoid outages and ensures essential services like food and medicine remain accessible even during short outages.
3. Maximizing the Use of Renewable Energy
Energy storage enables renewable generation to meet demand while offering services like static reserve, electricity frequency and voltage regulation and restart capability. Furthermore, storage systems can begin discharging power back to the grid in far less time than it takes traditional thermal plants to start up.
Similar to how refrigerators store food for days at a time, energy storage allows renewables such as solar or wind power to remain functional even when their output falls off temporarily. Furthermore, energy storage enables businesses and homes to participate in demand response programs without having to drastically decrease usage during times of peak energy prices.
Longer term, integrating an on-grid energy storage system (ESS) with solar and wind resources will enable these sources to avoid cutting back their output in response to supply requests from grid operators, speeding up the clean energy transition. ESS systems offer flexibility that enables renewables to reach their full potential while speeding up clean energy transition.
4. Smoothing Out Demand
Energy storage’s ability to balance supply and demand allows greater penetration of renewable energy sources. By storing excess generation and releasing it at peak demand times, storage helps reduce curtailment of renewable sources as well as improve power quality by eliminating momentary spikes, sags, or outages on the grid.
Energy storage systems also offer additional services like static reserve, frequency and voltage regulation, and restarting to help ensure the stability of electric grids on a second-by-second basis. These benefits help prevent blackouts while keeping energy costs affordable for communities.
Energy storage technology can be deployed at both large scales to feed the grid, and on smaller scales in homes and businesses as behind-the-meter solutions. When combined with smart meters, this allows consumers to reduce electricity costs by cutting their demand and participating in energy storage markets.
5. Adding Value to the Grid
Storage systems not only help integrate renewables, but can also offer valuable ancillary services like static reserve (controlling electricity frequency and voltage), which are typically provided by traditional generators. Energy storage also offers fast response times when unexpected fluctuations arise by providing energy quicker than traditional thermal power plants can.
Commercial and industrial customers can utilize energy storage systems (ESSs) to reduce demand charges (fees calculated based on peak usage during billing periods), shift energy use away from peak hours, and participate in utility demand response programs without impacting operations.
Communities located outside the grid can benefit from community solar coupled with energy storage to form microgrids that provide backup power during short power outages and provide backup during longer outages.