Energy storage helps meet consumer demands for electricity without straining the electric grid, thus avoiding price spikes for consumers. When integrated with community solar and aggregated home and business rooftop solar projects, community-level microgrids or resilience hubs may be created as a result.
Electricity storage offers many of the same grid services currently provided by fossil fuel peaker plants – which operate only during times of high electricity demand – while supporting renewables integration into the grid.
1. Rechargeable Batteries
Battery energy storage enables any excess renewable energy generated at one location to be distributed at another time, creating an more sustainable electricity grid and mitigating intermittency associated with renewable sources like wind and solar power.
Rechargeable batteries or secondary cells (formerly energy accumulators) operate by way of an irreversible chemical reaction that allows current to flow from negative to positive pole of an electrochemical cell, and back again again through electron migration triggered by external current applications; this power can then be used to recharge the battery.
Power storage solutions such as this rechargeable battery can help lower demand on the national grid during periods of high consumption, or as backup power for homes during blackouts. They may also be connected to bidirectional EV chargers and solar panels to generate home energy production and reduce energy bills further. Rechargeable batteries should always be stored in cool, dry places as exposing them to extreme temperatures can significantly decrease their performance and lifespan.
2. Flow Batteries
Flow batteries store electrolyte in tanks before pumping it through a cell stack when operators want to generate power. This system offers flexible energy and power sizing as well as long life span with reduced maintenance requirements and tolerance of overcharge/discharge cycles.
Research and development efforts are currently being undertaken on various chemistry approaches that aim to lower upfront costs, increase energy density and ensure safety. Research is crucial for pushing this new technology closer towards mainstream adoption.
PNNL researchers are creating models to better understand the physical and chemical processes in batteries, including lattice Boltzmann, molecular dynamics and density function simulations of porous media. Furthermore, they will be creating stack-level network models to determine how energy is stored and converted in flow batteries; these will help designers tailor these systems to specific application requirements, while being safe and robust enough for grid storage applications.
3. Electromagnetic Storage
Energy storage works to balance fluctuating supply and demand on the grid by transforming renewable electricity into mechanical, thermal or chemical energy for storage purposes, then back again as power. This process provides an important service in helping keep prices consistent across the nation’s energy network.
Electromechanical energy storage technologies like flywheels and superconducting magnetic energy storage (SMES) devices store both potential and kinetic energy through electromagnetic field movements, with minimal resistance loss over other forms of storage devices.
Other forms of energy storage, like pumped hydro or compressed air, rely on reversible electrochemical reactions to convert mechanical energy to electricity in an inefficient but time-consuming process, making these options less suitable for peak demand periods.
Energy storage provides multiple benefits to the grid, including frequency regulation and voltage control. It can also help manage demand spikes more smoothly – leading to savings for consumers – which in turn may reduce energy prices overall. These systems may be installed anywhere along the supply chain such as transmission network nodes, distribution nodes, generator sites or co-located with solar or wind generation facilities.
4. Thermal Storage
Thermal energy storage systems temporarily store electricity as heat or cold to be used later, using various technologies like phase change materials or crushed rock. By doing so, these systems help reduce fluctuations between supply and demand as well as increasing renewables’ share in the grid while improving power generation reliability.
Berkeley Lab researchers are pushing this technology further by developing storage that doesn’t provide general-use electricity but instead targets specific areas like air conditioning for buildings or state government offices. Ice is frozen overnight using off-peak electricity before melting during the day to reduce air conditioning’s electricity use.
Energy storage is key to decarbonizing industry, providing access to affordable and reliable energy in marginalized communities, and avoiding price spikes during high demand (much as rideshare apps do when peak demand occurs). Furthermore, unlike coal plants which may take hours to restart again, storage devices provide electricity quickly back onto the grid.