HOUSTON–(BUSINESS WIRE)–Overwatch Capital (“Overwatch”) and Idemitsu Kosan Co., Ltd. (“Idemitsu”) today announced a strategic partnership to support the development of next-generation, energy-resilient AI data centers across ten U.S. states. The collaboration includes an investment by Idemitsu into Overwatch Capital and the launch of Idemitsu’s nationwide natural gas supply operations in the United States. Through the partnership, Idemitsu will supply natural gas to on-site power generation systems capable of providing up to 1 gigawatt (GW) of natural gas to support the next generation of AI driven data centers.
The partnership will ensure firm, long-term natural gas supply for tenants across Ohio, Texas, Illinois, Utah, Colorado, Arizona, Georgia, Nevada, South Carolina, and Pennsylvania, powering high-density AI compute through both grid-connected and private-grid models.
The partnership combines Overwatch’s SIDE Platform with Idemitsu’s strategic entry into U.S. natural gas supply and its broader expertise in global energy solutions. Together, the companies will accelerate the deployment of parallel data center builds to meet unprecedented demand from hyperscalers, GPU-cloud providers, and institutional investors seeking purpose-built, energy-resilient platforms for AI compute at scale.
“This partnership sets a new standard for high-density, low-carbon AI data centers, empowering our clients to deploy class-leading compute at scale through Overwatch’s SIDE Platform while advancing resiliency and sustainability in the communities we serve,” said Sean Lyle, Managing Partner, at Overwatch Capital.
Overwatch’s SIDE Platform integrates on-site natural-gas generation, battery storage, advanced cooling, and proprietary energy management systems to create hyper-scalable sites designed for maximum uptime, efficiency, and sustainability. Each facility supports next-generation GPU clusters, liquid-cooling systems, and ultra-high rack power densities.
As part of this partnership, Idemitsu will supply natural gas to Overwatch’s on-site generation systems and explore additional energy services for data centers, such as immersion cooling technologies, diesel supply for backup systems, and potential deployment of battery energy storage solutions. These initiatives leverage Idemitsu Group’s decades of expertise in energy, materials, and industrial operations across Japan and international markets.
“This collaboration with Overwatch Capital marks an important step in connecting reliable, lower-carbon energy with next-generation data infrastructure. Demand for electricity to support AI is expected to grow rapidly, and through our natural gas supply operations in the United States, we are committed to providing sustainable and efficient energy solutions that contribute to the advancement of an AI-enabled society,” said John H. Happ III, Senior Vice President of Idemitsu Americas Holdings.
Overwatch Capital’s SIDE Platform can now provide tenants the following:
- Mission-critical resiliency: Multi-layered backup and microgrid independence ensure maximum uptime for AI clusters.
- Data security: Dedicated, high-integrity environments engineered for enterprise- and cloud-scale operations.
- Sustainable performance: Natural-gas generation paired with BESS reduces carbon intensity, while advanced energy technologies support efficient generator operations.
- Comprehensive energy solutions: Integration of low-emission molecules, fuel cells, immersion cooling, diesel backup supply, and other energy services supported by Idemitsu’s global capabilities.
- Rapid expansion: Idemitsu’s investment and U.S. energy operations enable simultaneous multi-market deployment across ten target states.
- Grid flexibility: Dual private-grid and grid-supplied energy models reduce interconnection risk and accelerate site delivery.
Advisory and Financing
Marathon Capital served as exclusive financial advisor to Overwatch in the formation of this partnership. As Overwatch’s SIDE Platform finalizes tenant relationships across its national portfolio, Marathon Capital will lead the structuring and capitalization of both corporate and project-level financing, positioning the platform as a bankable, energy-backed solution for institutional investors and hyperscale tenants alike. Overwatch anticipates starting two projects in 2026, Resilience Dallas–Fort Worth and Resilience Columbus (Ohio).
“This collaboration represents the convergence of two global capabilities — Idemitsu’s dependable energy support and Overwatch’s ability to integrate that energy directly into the compute layer,” said Gerry Willinger, Managing Director at Marathon Capital. “It was a pleasure to work with both Idemitsu and Overwatch in forming this transformational partnership.”
“By combining deep energy market expertise with digital infrastructure innovation, Idemitsu and Overwatch are building the physical foundation to enable AI scale — positioning Overwatch as a key partner and gateway for tenants seeking resilient, financeable, and scalable energy solutions,” added J. Patrick Brandt, Vice President at Marathon Capital.
About Overwatch Capital
Overwatch Capital is a forward-thinking investment platform specializing in the development and operation of sustainable digital infrastructure, with a strong focus on energy innovation and environmental stewardship. Through its SIDE Platform and Resilience Series data centers, Overwatch integrates energy and compute to deliver efficient, scalable solutions for high-demand AI and cloud applications.
About Idemitsu Kosan Co., Ltd.
Idemitsu Kosan Co., Ltd. is one of Japan’s largest energy and industrial companies, engaged in fuels, petrochemicals, high-performance materials, lubricants, renewable energy, and advanced energy services. Through Idemitsu Americas Holdings, the company is expanding its U.S. presence with nationwide natural gas supply operations and exploration of energy services for data centers, including immersion cooling, diesel backup support, and battery storage solutions.
About Marathon Capital
Marathon Capital is the largest independent investment bank dedicated to servicing the clean economy. Throughout its 25-year history, the firm has played a pivotal role in many of the groundbreaking and transformative transactions for new and emerging sectors, consistently delivering exceptional results for its clients. The firm is a leading global financial adviser across M&A, equity capital markets, debt capital markets, tax credits, offtake, and energy transition. Marathon Capital is headquartered in Chicago, with offices in New York, Houston, San Francisco, San Diego, London, and Calgary with local presence in Madrid and Seoul.
Contacts
Overwatch Capital
Megan Hulsey
Director of Marketing
Email: [email protected]
Idemitsu Americas Holdings Corporation
John H. Happ III
Senior Vice President: Gas & Power
Email: [email protected]
Marathon Capital
Andrea Rosko
Head of Marketing & Communications
Email: [email protected]
