This month, we're pleased to feature Spring Lane Capital (SLC), a long-standing client of Mintz's Sustainable Energy & Infrastructure Practice. SLC is a private equity firm based in Boston and Montreal, focused on providing hybrid project capital for sustainability solutions in the energy, food, water, waste, and transportation industries.
SLC's structured financial model seeks to tap into some of the fastest-growing segments of these markets that more traditional forms of project capital cannot access due to their scale and the limitations of existing investment models. SLC's pioneering "Developer U" is a first-of-its-kind effort to build the ecosystem of developers of sustainable infrastructure projects.
In July 2025, SLC announced its latest round of financing for Soluna Holdings, Inc., a developer of green data centers for intensive computing applications. Soluna is on a mission to make renewable energy a global superpower, using computing as a catalyst. The company designs, develops, and operates digital infrastructure that transforms surplus renewable energy into global computing resources. Soluna's pioneering data centers are strategically co-located with wind, solar, or hydroelectric power plants to support high-performance computing applications, including Bitcoin mining, generative AI, and other computing-intensive applications.
SLC's $20 million funding will allow Soluna to begin construction on Project Kati 1, a new facility designed to accommodate approximately 12,000 next-generation Bitcoin mining rigs. SLC and Soluna previously signed an agreement to extend up to $100 million of additional project-level capital for Soluna's growing data center pipeline for Bitcoin and AI, subject to certain conditions precedent.
In September 2025, Soluna also announced the close of scalable credit facility in an amount of up to $100 million from Generate Capital, a leading infrastructure investment firm. The initial $12.6 million draw will fund refinancing and construction of active data center projects, with additional capital support for Soluna's 1 gigawatt and expanding pipeline. This financing further illustrates Soluna's exciting innovations in the sustainable energy sector.
"Spring Lane Capital has walked alongside Soluna on our path to growth since the beginning with an investment in Project Dorothy," said John Belizaire, CEO of Soluna. "We expect these funds to fuel the construction of the first 35MW of the 83MW phase of Kati 1, which expands Soluna's Texas fleet for Bitcoin Hosting."
"We continue to invest in and be strategic supporters of Soluna because they continue to take steps toward sustainable high-performance computing and meeting green data center demand," said Rob Day at SLC. "We're looking forward to construction getting underway at Project Kati so that Soluna can continue expanding its green computing power."
Mintz is proud to support the team at Spring Lane Capital and to work together with SLC, its investee companies, and other business partners on these cutting-edge, trailblazing infrastructure projects. We're excited to witness their continued growth and success in the sustainable energy field.
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