Energy Storage

A Battery Energy Storage System (BESS) is a large-scale installation of batteries connected to the electrical grid. BESS can store excess renewable energy when production is high and discharge it during peak demand, providing grid stability, capacity firming, and energy shifting. Grid-scale BESS typically range from a few MW to hundreds of MW in capacity.

In 2025, a record 112 GW (307 GWh) of energy storage was installed globally. BloombergNEF forecasts 158 GW (459 GWh) for 2026 — a 41% increase. Annual additions are projected to reach 308 GW by 2036, with cumulative capacity hitting 2.9 TW (10.5 TWh).

Lithium-ion batteries use lithium ions as the charge carrier, while sodium-ion batteries use sodium ions. Sodium is 1,000x more abundant than lithium, making SIBs potentially much cheaper. SIBs are compatible with existing Li-ion manufacturing lines (drop-in), but currently have lower energy density (95-175 Wh/kg vs. 150-280 Wh/kg for Li-ion). SIBs are best suited for stationary storage and budget EVs.

LDES refers to energy storage systems that can discharge for 10 hours or more — compared to the 2-4 hour duration of typical lithium-ion BESS. LDES technologies include iron-air batteries, flow batteries, compressed air, thermal storage, and gravity systems. LDES is critical for bridging multi-day gaps in renewable generation.

Major automakers including Toyota, BMW, and Mercedes-Benz are targeting 2026-2028 for solid-state batteries in vehicles. QuantumScape, Solid Power, and Samsung SDI have pilot production lines operational. Mass production and cost competitiveness is most realistically expected in the 2028-2032 timeframe.

AI data centers require 24/7 reliable power with massive and variable loads. Energy storage supports data centers by: (1) bridging grid interconnection delays, (2) managing sudden AI workload spikes, (3) providing clean backup power replacing diesel generators, and (4) integrating with renewables for 24/7 carbon-free energy. Over 230 GW of data center projects have been announced in the US alone.

A Virtual Power Plant aggregates distributed energy resources — home batteries, EVs, solar systems, and commercial storage — into a single grid-connected asset. VPPs allow these distributed resources to participate in wholesale energy markets, provide grid services, and earn revenue for owners. VPPs are a growing trend in the energy-as-a-service model.

Yes. Form Energy is commercializing iron-air batteries targeting $20/kWh — 1/10th the cost of lithium-ion. The technology uses reversible rusting of iron and can discharge for 100+ hours. Form Energy has orders from Georgia Power and is building a manufacturing facility in West Virginia. Iron-air batteries are heavier and larger than Li-ion, but this is irrelevant for stationary grid storage.

CATL (Contemporary Amperex Technology) is the world's largest battery manufacturer, targeting 1TWh (terawatt-hour) annual production capacity by 2028. This is enough to power ~20 million EVs per year. CATL holds 37% of the global EV battery market and is expanding with LFP and sodium-ion production lines. The company is also developing condensed matter batteries with 500 Wh/kg energy density for electric aviation.

Virtual power plants earn revenue through multiple streams: (1) wholesale energy market participation — selling stored electricity during peak prices, (2) ancillary services — frequency regulation and grid stability payments, (3) capacity markets — payments for being available to discharge, (4) demand response — payments for reducing load during grid stress. Home battery owners in VPP programs like Tesla Virtual Power Plant in California earn $1-2/KWh annually.