Three Tenants Take Full Capacity of ECL's 35 MW FlexGrid Data Center in the US

ECL, the Silicon Valley data center developer, that CSC1, its 35MW facility in Santa Clara, Calif., has been fully committed by three tenants, with no remaining capacity available. Deployment of tenant workloads begins in the first quarter of 2027, and the company expects full completion by the third or fourth quarter of that year.

Leasing Complete Before Construction Finishes

The tenants are described as established AI cloud platforms alongside inference-focused startups backed by leading AI research organizations. All three will run AI inference workloads at the site.

Reaching full commitment eight months after the facility was first announced in April 2026, and while construction is still underway, is the headline outcome for the company. ECL credits its modular block architecture and behind-the-meter power generation, an approach it says shortens the interval from purchase order to keys to nine to 12 months in metro markets, against the two to three years it says is typical for conventional data centers dependent on the grid.

A Operator's Calculus in a Power-Starved Market

Yuval Bachar, ECL's co-founder and chief executive, framed the leasing result as a response to the arithmetic facing AI operators across the Bay Area. "Every major AI operator in the Bay Area is doing the same math right now, weighing years-long interconnection queues against inference demand that compounds monthly," Bachar said. "These three tenants chose CSC1 because FlexGrid gets them to production in months, not years.

They are deploying next quarter instead of waiting for a utility to approve a substation." Bachar also noted that inference workloads must sit close to people, data, and applications, often in and around major cities, where the grid rarely has 50 or 100 spare megawatts on hand.

The leasing demand lands against a backdrop of tightening electricity supply for the industry. 451 Research projects that US data center electricity demand will nearly triple over the next five years, hitting roughly 183.2 GW by the end of 2030. Bloomberg, meanwhile, reports that half of all US data center projects this year are facing delays or cancellations because of power constraints.

How the Site Is Powered

CSC1 runs on FlexGrid, ECL's power architecture, which blends three sources: up to 5 MW of on-grid electricity, up to 30 MW of natural gas generation via microturbines and fuel cells, and up to 5 MW of hydrogen power.

Battery systems handle transient control and backup duty. The mix is not fixed. It can shift over time according to operational needs and energy market conditions, and ECL says the facility architecture needs no redesign when fuel sources change.

Density, Cooling and Efficiency Targets

The facility launches supporting rack densities up to 150 kW, with headroom in its design for future densities of 250 kW and beyond as tenant requirements evolve. It is ready for NVIDIA's GB300 and Vera Rubin architectures, uses direct-to-chip liquid cooling, and targets a PUE below 1.15.

Cooling is a layered affair, combining direct-to-chip, air, and hydrogen byproduct water-based systems, with the design intended for Tier III-level reliability. Water use is one differentiator ECL highlights. When hydrogen serves as a FlexGrid power source, the water byproduct from fuel cell generation feeds the cooling loop, removing the freshwater draw that has become a growing concern for data center operators in drought-prone California.

A Supply Chain Strategy Built Around Smaller Parts

The modular block approach is also positioned as a supply chain hedge. Rather than sourcing a small number of large components, such as utility-scale transformers that now carry lead times beyond 120 weeks, the design pulls in many smaller ones, allowing ECL to work through a supply chain different from that of traditional data center operators.

ECL builds its blocks in parallel and omits conventional UPS systems, which the company says further compresses the construction schedule. The sequencing also allows tenants to run production workloads in early blocks while later phases of the facility remain under construction, a staging that matches the Q1 2027 start date despite the later overall completion window.

Three More Sites Open for Inquiries

Alongside the CSC1 announcement, ECL has opened three additional sites, CSJ1, CSU1, and CSU2, to tenant inquiries. CSJ1 is named as the next site in the company's planned distributed inference network across the Bay Area. All three follow the same FlexGrid architecture and are designed for inference-dense AI workloads at a scale of 25 to 35 MW. Prospective tenants are directed to contact ECL through its website for capacity planning and early site engagement.

Who ECL Is

ECL builds high-density, AI-ready data centers designed for locations where traditional power infrastructure falls short. Its FlexGrid microgrid architecture and ECL Lightning real-time management platform combine grid power, natural gas, batteries, and hydrogen fuel cells to deliver power shaped for AI and inference workloads.

The company brought what it describes as the world's first operational hydrogen-powered AI data center online at its MV-1 site in Mountain View, California, in 2024, and is now scaling FlexGrid across US and international markets. ECL is backed by Molex Ventures and Hyperwise Ventures.