Form Energy & Rondo: Industrial Scaling of 100-Hour Storage

The transition to a baseload-renewable grid has reached a critical velocity. Today, two of the most prominent players in the **Long-Duration Energy Storage (LDES)** market, **Form Energy** and **Rondo Energy**, announced multi-gigawatt industrial contracts that prove the 100+ hour energy buffer is no longer a pilot project—it is a mandatory layer of the modern industrial stack.

Form Energy’s "Iron-Air" Multi-Day Buffer

Form Energy has secured a massive contract with a major national utility to deploy a 2GW/200GWh **Iron-Air battery** system in the US Midwest. Unlike traditional lithium-ion batteries that are optimized for 4-hour discharge, Form’s system utilize the reversible oxidation (rusting) of iron to store energy for up to **100 hours**. This allows the grid to utilize intermittent wind energy as a reliable "baseload" resource, even through multi-day weather patterns with zero wind. By utilizing iron—one of the most abundant and low-cost materials on Earth—Form has reduced the cost of multi-day storage to roughly 1/10th that of lithium-ion, effectively solving the "intermittency argument" for clean energy.

Rondo’s "Heat Battery" for Heavy Industry

Simultaneously, **Rondo Energy** is scaling its **"Heat Battery"** technology to decarbonize thermal industrial processes. Rondo’s units store intermittent renewable electricity as high-temperature heat in specialized refractory bricks, reaching temperatures of up to 1,500°C. This heat can be released as high-pressure steam for industries like chemical manufacturing and food processing (such as the recently announced **Heineken** partnership). By providing a carbon-free heat source that is cheaper than burning natural gas, Rondo is addressing the "hardest 20%" of global emissions—industrial heat—which has historically been ignored by traditional battery startups.

The AI Energy Buffer

The primary driver for this sudden surge in LDES scaling is the **AI Data Center boom**. Hyperscalers are finding that current national grids cannot support the constant, high-intensity loads of GB200 clusters without on-site stabilization. LDES acts as the "thermal and electrical buffer" that allows an AI factory to operate 24/7 on 100% renewable power. Both Form and Rondo are reportedly in talks with **Microsoft** and **Google** to collocate storage units directly with upcoming gigawatt-scale data center campuses.

As the **Physical AI** revolution moves into the factory floor, the "plumbing" of the grid is being redesigned for a world of constant compute. The Form-Rondo milestones prove that the ultimate winner of the energy transition will be the nation that can most effectively store the wind and the sun for the days when they don't shine.