Form Energy & Rondo: Industrial Giants Embrace Long-Duration Storage

The transition to a baseload-renewable grid has reached a critical scaling point. Today, two of the most prominent players in the **Long-Duration Energy Storage (LDES)** market, **Form Energy** and **Rondo Energy**, announced major multi-gigawatt industrial contracts that prove the feasibility of the 100+ hour energy buffer. These deals, with partners including **Microsoft** and **Heineken**, mark the end of the "intermittency argument" for clean energy.

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

Form Energy has secured a massive contract with **Microsoft** to provide on-site storage for a new gigawatt-scale AI data center in the US Midwest. The system utilizes Form’s proprietary **Iron-Air battery** technology, which stores energy through the reversible oxidation (rusting) of iron. Unlike lithium-ion batteries, which are optimized for 4-hour discharge, iron-air systems can provide constant power for up to **100 hours**. This allows the AIDC to operate at full capacity through several days of low wind or cloud cover, utilizing Midwestern wind-farms as a reliable "baseload" resource. Form Energy is reportedly using its recent Series F funding to double its manufacturing capacity in West Virginia to meet the surging demand from the AI sector.

Rondo’s "Heat Battery" for Industrial Decarbonization

Simultaneously, **Rondo Energy** has signed a landmark deal with **Heineken** to decarbonize thermal processes in several European breweries. Rondo’s technology uses **brick-based thermal storage**, where intermittent renewable electricity is used to heat specialized refractory bricks to temperatures exceeding 1,500°C. This heat can be stored for days and then released as high-pressure steam for industrial use. By providing a "thermal battery" that is cheaper than burning fossil fuels, Rondo is solving the hardest part of the energy transition: industrial heat. The Heineken deal is the largest commercial deployment of a heat battery to date, signaling a shift in how heavy industry views renewable electrification.

The End of the Peaker Plant?

The simultaneous scaling of electrochemical (Form) and thermal (Rondo) LDES technologies represents a fundamental threat to traditional natural gas "peaker" plants. By providing a multi-day buffer that is cost-competitive with fossil fuels, LDES allows the grid to utilize the lowest-cost renewable energy even when the sun isn't shining. VCs have poured over **$2 billion** into the sector in the first half of 2026 alone, betting that the nation that owns the "LDES stack" will own the unit economics of the artificial intelligence era.

As the **Physical AI** revolution continues to automate the factory floor, the "plumbing" of the grid is being redesigned for a world of constant, high-intensity compute. The Form-Rondo milestones prove that sustainability and scalability are finally being co-engineered into the foundation of the global economy.