Batteries play a crucial role in making renewable energy sources like solar and wind power more viable options for widespread grid integration. As the production and capability of batteries continues to improve, battery storage is becoming an increasingly important technology for enabling the large-scale adoption of intermittent renewable power sources. Various types of batteries are being developed and applied to store excess renewable energy and discharge it when the sun isn’t shining or the wind isn’t blowing. Some of the most promising battery technologies currently being advanced for renewable energy storage applications include lithium-ion, redox flow, zinc-bromine, and sodium-based batteries.

Lithium-ion battery technology has seen tremendous advancements in recent decades and remains the dominant chemistry used for most electric vehicles and consumer electronics. For utility-scale energy storage, lithium-ion is also increasingly common due to its high energy density and relatively fast recharge rates. Manufacturers are working to drive down costs through innovations in materials and production processes. longer-lasting electrolytes and electrodes are extending cycle life. New lithium-ion chemistries using lithium iron phosphate, lithium titanate, and high-nickel cathodes offer improved safety characteristics compared to earlier generations. Startup companies like Ambri, Enervault, and CellCube are developing liquid metal batteries that could store renewable energy for weeks at a time at grid-scale with lithium-ion-like recharge speeds.

Redox flow batteries offer an alternative battery architecture well-suited for multi-megawatt, prolonged duration applications. With their liquid electrolytes circulating in external tanks disconnected from the battery structure, flow batteries can be scaled up or down according to power and storage needs. They also have a potentially longer lifespan than lithium-ion. Recent flow battery advancements include improved electrolyte chemistry and materials like all-vanadium, zinc-bromine, and polysulfide bromide designs that maintain high roundtrip efficiency over thousands of charge/discharge cycles. Companies such as Sumitomo Electric, Redflow, and ESS Inc are optimizing flow battery chemistries and system designs for renewable energy storage.

Beyond lithium-ion and flow batteries, other types are in earlier stages of commercialization but showing promise. Zinc-bromine batteries can deliver energy at competitive costs for multi-hour storage and are stable in high ambient temperatures. Form Energy is developing a low-cost iron-air battery suitable for seasonal storage of renewable energy for the grid. Ambient temperature sodium-ion and sodium-sulfur batteries offer lower costs than lithium-ion and could provide renewable energy storage measured in days rather than hours. These technologies are still in the demonstration phase but may gain traction if cost and performance targets are met.

All of these battery innovations aim to overcome challenges limiting renewable adoption like the intermittent nature of wind and solar resources. With sufficient energy storage capacity, renewable power can be available on-demand around the clock to displace fossil fuel generation. Batteries coupled with variable renewable sources improve power quality and grid stability compared to intermittent wind and solar alone. The goal of battery manufacturers is to achieve costs low enough that renewable energy plus storage becomes cheaper than new fossil fuel infrastructure over the lifetime of the projects. If scalable, economical battery storage solutions continue advancing, they have the potential to transform electricity grids worldwide and enable a transition to high shares of renewable energy.

Battery technology is rapidly progressing to enable the integration of higher levels of variable wind and solar power onto electricity grids. Lithium-ion remains strongly positioned for short-duration applications while newer battery types like redox flow, sodium, and iron-air show promise for longer-duration storage necessary for renewable energy at multi-day scale. With ongoing cost reductions and performance improvements, it’s realistic to envision a future with terawatt-scale amounts of wind and solar generation working symbiotically with battery storage to supply clean, reliable electricity around the clock. Further battery innovations will be integral to fully realizing that renewable energy future.