ENERGY STORAGE

Energy storage is the process of capturing and storing energy for use at a later time. In the context of the electric grid, energy storage can be used to store excess energy generated by renewable sources (such as wind and solar) during periods of low demand, and then release it during periods of high demand when there is not enough electricity being generated by the power grid to meet that need. 

Energy storage can be used for various applications, including residential and commercial backup power, transportation, and grid stabilization. When it comes to the electric grid, energy storage can help integrate renewable energy sources, such as wind and solar power, by storing excess energy generated during times of low demand and releasing it during peak demand periods. This can help address the intermittent nature of renewable energy sources, which may not always be available when needed. 

Today, the grid is balanced by using flexible fossil fuel resources to balance supply to meet demand. In the same way, energy storage will help to smooth out the supply and demand of electricity so that renewable energy sources can be better integrated into the grid and their overall contribution of generation cost-savings to the grid can be maximized.

In addition, energy storage can also help reduce the need for expensive new power plants that are solely used to provide electricity during periods of high demand. By storing excess energy during periods of low demand and releasing it during peak demand, energy storage can help alleviate stress on the grid, making it more stable and reliable. 

There are many different types of energy storage technologies that can be used for the electric grid, including but not limited to: 

• Batteries: Batteries are a type of energy storage system that store electrical energy in chemical form. They can be used to store excess energy generated by renewable sources and release it when needed. 
• Pumped Hydro: Pumped hydroelectric storage involves pumping water uphill during times of low demand, and then releasing it through turbines to generate electricity during times of high demand. 
• Compressed Air Energy Storage (CAES): CAES involves compressing air and storing it in underground caverns, and then releasing it to generate electricity during times of high demand. 
• Thermal Energy Storage: Thermal energy storage involves storing heat or cold in an inexpensive medium such as rocks, liquid salt or cheap elements, and then using it to generate electricity as needed. 
• Gravitational Storage with Solid Masses: Similar to Pumped Hydro, excess electricity is used to move mass into position to be later converted to electricity allowing gravity to pull that mass earthward.
• Gas Production and Fuel Cells: Principally used with Hydgrogen, this type of energy storage uses excess power to produce a gas, and to store that fuel on site for later use in power generation using a fuel cell or traditional gas turbine. 

By using energy storage technologies, renewable energy sources can be better integrated into the electric grid, reducing the need for backup generation and helping to create a more affordable and reliable energy system. Advanced Power Alliance is working to push states and ISOs forward in the deployment of energy storage technologies, to more quickly bring their benefits to consumers.

As we move toward a cleaner, more resilient energy future, thermal energy storage (TES) is also emerging as a powerful tool to help balance the grid, reduce energy costs, and make better use of renewable resources like solar and wind. TES works by storing intermittent energy as heat or cold for later use—essentially acting as a thermal battery. This stored energy can be used to heat or cool buildings, drive industrial processes, or generate electricity when demand is high and renewable generation is low.