Energy Storage Systems (ESS) absorb excess generation from the grid or renewable and deliver power later. They are used in multiple segments of the electricity grid in transmission and distribution networks and at the residential and commercial levels. Like the uninterruptible power supply under your desk, energy storage provides a backup for critical equipment.
Wind Energy Storage
Wind energy storage is used with wind turbines to improve electricity reliability and help lower overall energy costs. The storage system takes D.C. power from the wind turbine inverter and converts it to A.C. power for use on the grid. When wind production dips, the stored energy is used to offset the drop in power output from the turbine. It helps balance the variable wind energy generation and reduces the need for on-demand gas power to fill the gaps. Wind storage is also important for communities far from the electrical grid, including rural areas and islands. These communities are vulnerable to power outages and spikes in electricity prices. Using energy storage in conjunction with community solar or aggregated home and commercial building rooftop solar projects can help these communities establish microgrids or resiliency hubs that are less dependent on the electrical grid.
As wind energy storage becomes more popular, it’s important to understand battery safety and how it relates to these systems. Beyond the attention-grabbing headlines about battery failures, several important factors influence how safe an energy storage system is, including product design, safety testing, community preparedness, and 24/7 remote monitoring. Energy storage is a critical part of the clean energy landscape, helping to ensure that renewables are reliably integrated into the grid and that we can meet our clean energy goals.
Battery Storage
Unlike traditional power plants, which produce electricity at the exact moment it is needed, BESSs can store and discharge energy to match demand. This flexibility helps balance the electric grid, strengthening its reliability. A battery storage system includes an inverter and an energy management system (EMS). An inverter converts the direct current (D.C.) from the batteries into the alternating current used for facilities such as a commercial building or home. The EMS monitors and controls the power flow throughout the system. Today, lithium-ion batteries are the most popular battery technology for ESSs. This same technology is used in cell phones and electric vehicles, and it’s also being paired with solar P.V. to maximize the value of solar-generated energy. These battery systems operate in several locations worldwide, including commercial buildings and residential homes. Battery Energy Storage System technologies are critical to replacing fossil fuels with renewable and providing various other grid services, like frequency response and regulation, peaking capacity, and backup power. These technologies are also lowering energy costs and eliminating pollution. Design, engineering, and construction represent the largest domestic supply chain for battery storage systems in the United States. However, as the market grows, more companies must build local manufacturing facilities to meet demand.
Electric Vehicle Battery Storage
Electric Vehicle (E.V.) battery systems can be used to store energy for later use. This energy can be stored as current and then released when needed, reducing the need for electricity from power plants. There are many different types of batteries, but lithium-ion is the most popular for E.V.s. At a utility scale, these batteries can be combined with other technologies like solar to provide a wider range of services. Engineers at National Grid and other electricity grids worldwide must balance supply and demand on a second-to-second basis. The peaks and troughs in demand create opportunities for energy storage to help manage these fluctuations. Without energy storage, these peaks and drains would be met with expensive fossil fuel peaker plants. With energy storage, these plants can be decommissioned, and the cost of electricity for consumers is reduced. Battery energy storage can also reduce demand charges at E.V. charging stations by ‘shaving’ peak demand. It is done by storing electricity during low demand and releasing it during peak times at the station. It can significantly lower the cost of E.V. charging. The opportunity for E.V. battery energy storage to support the grid depends on several factors, including the rate of battery degradation, consumer participation in the vehicle-to-grid and second-use markets, and geographic and temporal temperature variation.
Solar Energy Storage
Storage systems for solar power provide various benefits, including financial savings on electricity bills and backup power during grid outages. They can increase the capacity for renewable energy, improve community resilience in urban environments, and lessen dependency on fossil fuels. Storage is an essential complement to solar and other renewables because many of these sources are intermittent. Storage allows excess renewable generation to be banked during high production/low demand and then released during low production/high demand periods. Residential solar customers use various technologies and innovations to store the electricity their systems produce. Batteries are by far the most popular option. By allowing homeowners to go off-grid, these systems can lessen their reliance on the electric grid and supply electricity after sunset or during a power outage. Other types of energy storage include thermal and mechanical. Energy is stored through thermal storage, which uses a substance such as water, molten salts, or sand in an insulated tank. The system can then release the stored energy to generate electricity or provide heat. SwRI chemical engineers have developed a novel encapsulation formulation of molten salt capsules for this purpose. Energy storage will be critical to the U.S. achieving our clean energy goals.
