Soluna Holdings, Inc

Unless the context requires otherwise in this Annual Report, the terms “SHI,” “Soluna,” the “Company,” “we,” “us,” and “our” refer to Soluna Holdings, Inc. together with its consolidated subsidiaries, “SDI” refers to Soluna Digital, Inc. “SCI” refers to Soluna Computing, Inc., formerly known as EcoChain, Inc., “Soluna Cloud” or “Cloud” refer to Soluna Cloud, Inc., and “SEI” refers to Soluna Energy, Inc. Other trademarks, trade names, and service marks used in this Annual Report are the property of their respective owners.

Overview

Our mission is to make renewable energy a global superpower using computing as a catalyst.

We develop and operate digital infrastructure that taps into a growing global opportunity: the convergence of renewable energy and High-Performance Computing (HPC). We call this modelRenewable Computing™.

Across the world, vast amounts of clean energy go to waste due to curtailment. At the same time, there is a critical shortage of power for energy-intensive infrastructure like AI, HPC, and Bitcoin mining. Renewable Computing™ bridges this gap—unlocking stranded renewable energy and turning it into scalable computing power.

We build, own or co-own, and operate data centers co-located with wind, solar, and hydroelectric plants. Our modular and scalable design supports high-throughput, batchable applications such as AI, Bitcoin, and—soon—HPC workloads. These facilities are managed byMaestroOS™, our proprietary operating system (“MaestroOS”), which continuously analyzes signals like local power pricing, weather, grid demand, and market conditions to optimize performance and economics.

This intelligent orchestration enables long-term asset monetization and attractive returns on invested capital.

Our approach is purpose-built for the energy transition. We specialize in curtailment solutions, working closely with leading renewable energy developers to access underutilized, low-cost power. Our behind-the-meter model allows us to draw energy directly from the plant or the grid, while also providing demand response services—reducing costs and enhancing grid resilience.

A key strategic advantage is our model of co-locating data centers directly with renewable power generation assets. By building behind the meter, we are able to bypass long interconnection queues and source electricity directly from the generation site. This structure not only improves power economics, but also accelerates time-to-market—an increasingly important factor for companies with large, time-sensitive computing workloads such as AI and HPC.

With a repeatable strategy and a growing pipeline of projects, we are scaling a new category of digital infrastructure—one that energizes the grid, lowers computing costs, and advances a more sustainable future.

We operate across multiple business lines and generate revenue from four primary sources, as described below:

In 2024, our execution strategy was centered around four key initiatives:

Lines of Business

Bitcoin Mining Business

We engage in proprietary Bitcoin mining, a process that verifies transactions and secures the Bitcoin blockchain. This process involves the use of specialized computing equipment to solve complex cryptographic algorithms. Miners compete to solve these algorithms; the first to do so is awarded a predetermined number of newly issued Bitcoins (the “Block Reward”) and any transaction fees associated with that block.

We participate in one or more mining pools—collaborative networks of miners who combine computing power to improve the probability of earning rewards. Block Rewards earned by the pool are distributed among participants based on each member’s proportional contribution. This model helps reduce revenue volatility compared to solo mining operations.

Our mining operations are energy-intensive and require significant computational resources. We operate data centers equipped with both proprietary and third-party hardware and software. Our proprietary data center operating system,MaestroOS, is used to optimize performance, manage power consumption, and increase operational efficiency.

Revenue from Bitcoin mining consists of Block Rewards and transaction fees and is recognized upon receipt in accordance with applicable accounting guidance. Upon receipt, all digital assets are promptly converted into U.S. dollars through the Coinbase cryptocurrency exchange.

The profitability of this business is affected by several variables, including the market price of Bitcoin, global network hash rate, mining difficulty, electricity and infrastructure costs, and mining pool fees. In addition, Bitcoin undergoes a periodic “halving” event approximately every four years, reducing the Block Reward and potentially impacting future revenue. For the year ended December 31, 2024, our Bitcoin Mining Business represented approximately 45% of total revenue.

Bitcoin Hosting Business

We provide colocation and hosting services for third-party Bitcoin mining customers at our data centers. Customers lease space based on their power requirements. Our current customer base includes several large-scale (“Hyperscale”) Bitcoin miners. Contracts typically range from 12 to 24 months in duration.

We offer two primary commercial structures:

In 2024, our Bitcoin Hosting Business accounted for approximately 50% of total revenue. Revenue in this business was concentrated among a small number of customers. One customer accounted for 56% of hosting revenue and 28% of total revenue in 2024. This customer terminated its agreement during the fourth quarter of 2024. As of March 2025, we replaced 100% of the lost hosting capacity with minimal operational disruption.

High Performance Computing (HPC) Business

In June 2024, we began providing GPU-as-a-Service in partnership with Hewlett Packard Enterprise Company (“HPE”), offering GPU resources to startups, enterprises, and GPU marketplaces for a fee. As further described in Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations” of this Annual Report, in March 2025, we terminated our agreement with HPE.

We are currently developing new infrastructure projects intended to support AI and HPC workloads. These efforts include engagement with potential joint venture partners, conducting site and feasibility studies, securing access to power and land, and performing other early-stage development activities.

Our first planned AI/HPC colocation project isProject Kati, which is in advanced development. Additional projects, including the announcedProject Rosa, are also in progress. For the year ended December 31, 2024, we generated minimal revenue from our HPC Business.

Demand Response Business

We provide demand response services to grid operators and utilities by leveraging our data centers as dispatchable energy resources. In select states where we operate, our data centers are enrolled in ancillary services programs that support grid reliability.

Under these programs, we commit to reducing a facility’s power consumption to a predetermined level when called upon by the grid operator. In return, we receive compensation for maintaining this dispatch capability, provided we meet specific performance criteria. For example, to qualify for compensation in a given period—typically monthly—the data center must meet minimum uptime and availability requirements.

For the year ended December 31, 2024, our Demand Response Business represented approximately 6% of total revenue.

Operations and Project Pipeline

As of December 31, 2024, we operate approximately 75 MW of capacity across two active sites located in Murray, Kentucky and Silverton, Texas. An additional 48 MW is under construction at our D2 project site, and as of December 31, 2024, we had over 403 MW of facilities in advanced development or near shovel-ready status. In total, our project pipeline includes approximately 2.6 gigawatts (GW) of renewable energy-powered data center developments.

A summary of our pipeline, current and anticipated operating locations are as follows (as of December 31, 2024):

We manage our data center operations usingMaestroOS. MaestroOS continuously monitors and analyzes a variety of real-time signals, including local electricity prices, weather conditions, Bitcoin market metrics, and grid demand signals, to optimize facility performance. In addition, MaestroOS is used to coordinate and execute our participation in demand response programs.

We finance the development and construction of our data centers through a combination of public equity offerings, debt instruments, and partnerships with project-level capital providers. As of December 31, 2024, we had two primary project-level financing partners:

Project Dorothy

During 2023, we transitioned our flagship data center Project Dorothy from construction to operations. This data center is co-located with Briscoe Wind Farm (“Briscoe”), a 150 MW wind power generation facility in Silverton, Texas. The project comprises three phases, D1A, and D1B, each 25 MW facilities, and D2 (48 MW).

Project Dorothy 1A

D1A is focused on Bitcoin Hosting for some of the industry’s hyperscale miners. There are approximately 7,800 Bitcoin miners installed at D1A, which as of December 31, 2024, resulted in a hashrate of approximately 1.01 EH/s. From May 2023 through December 31, 2023, D1A consumed over 11,900 MWh of Curtailed Energy and achieved a PUE of 1.03. For the year ended December 31, 2024, D1A consumed over 45,700 MWh of Curtailed Energy and achieved a PUE of 1.01.

D1A was constructed in partnership with SLC, a leading venture capital firm focused on sustainability solutions. SLC owns approximately 85% of the Class B Membership Units of D1A, while we own 15% of the Class B Membership Units of D1A and own 100% of the Class A Membership Units of D1A. After SLC achieves an 18% Internal Rate of Return hurdle, Soluna retains 50% of the profits on D1A.

Project Dorothy 1B

D1B is focused on proprietary Bitcoin Mining. There are approximately 7,700 Bitmain Antminer S19s, S19j Pro and S19j Pro+ machines installed, resulting in an installed hashrate of 817 PH/s. From July 2023 through December 31, 2023, D1B consumed over 10,600 MWh of Curtailed Energy and achieved a PUE of 1.03. For the year ended December 31, 2024, D1B consumed over 44,500 MWh of Curtailed Energy and achieved a PUE of 1.01. D1B is co-owned by Navitas, which owns approximately 49% of D1B, while we own the remaining 51%.

In November 2023, we completed registration of Project Dorothy in one of the ERCOT’s Demand Response Services (“DRS”) programs. This designation positioned Project Dorothy as a contributor to grid flexibility and resilience in the Texas power market, while also enabling us to diversify our revenue streams.

Under the DRS program, we commit to maintaining a specified level of curtailment capacity—measured as load reduction availability—on a monthly basis. When called upon by ERCOT, we are required to reduce the facility’s power consumption by the committed amount. In exchange, we receive compensation for maintaining this curtailment readiness, regardless of whether an actual dispatch occurs.

Participation in the program allows us to generate incremental revenue and offset power costs at Project Dorothy, enhancing its cost-efficiency. As a result, the facility ranks among the lowest-cost operators in the sector. Since registration, Project Dorothy has successfully fulfilled its obligations in the Winter, Spring, and Summer DRS periods, and is currently enrolled in the Fall standby period.

Project Dorothy 2

We began planning for the 48 MW expansion of Project Dorothy in 2023 – known as Project Dorothy 2. We partnered with SLC who agreed to finance up to $30 million of the project cost. We closed the initial financing contribution and operation agreement with SLC in July 2024 and broke ground in the third quarter of 2024. Initial energization and ramp-up is expected by the end of the second quarter of 2025. D2 features a superior financial waterfall structure and enhanced management and development fees for Soluna compared to D1A, allowing us to benefit from improved income once the facility is operational.

Project Grace

Project Grace is a 2 MW project located at the D2 site focused on next generation data center designs for AI. It contemplates new direct liquid cooling technologies, proprietary building and power designs – called Helix.

Project Sophie

Project Sophie is a 25 MW data center, based in Murray, Kentucky connected to the grid (“Sophie”). The project has a Power Purchase Agreement (“PPA”) that requires the curtailment of the site during certain hours of the day to help balance the Kentucky grid. We own 100% of the facility, which was completed in 2021.

Sophie is focused on Bitcoin Hosting of multiple large customers. The data center generates revenue via a combination of fixed services fees and profit share, while energy cost is passed through. For the year ended December 31, 2024, there are approximately 9,300 Bitcoin miners installed, resulting in an installed hashrate of approximately 1.03 EH/s and achieved a PUE of 1.03.

Our Growth Strategy

Our growth strategy is focused on expanding our pipeline of renewable energy-powered data center projects and accelerating their development through joint ventures, co-ownership structures, and other strategic partnerships. Over time, we intend to increase our ownership stake in these projects to enhance long-term value.

We believe our renewable energy project pipeline—currently estimated at over 2.6 gigawatts (GW)—represents our most valuable strategic asset. We believe this pipeline has the potential to support the development of approximately 300 to 400 MW of new digital infrastructure annually over the next six to eight years.

In parallel with new project development, we are refining our operational model across existing sites to position ourselves as a partner of choice for both AI/HPC colocation and Bitcoin Hosting.

We continue to grow our pipeline by increasing the number of Curtailment Assessments completed with power generation partners. These assessments serve as a precursor to securing exclusive power purchase agreements (PPAs), acquiring or leasing land, and executing other pre-construction development activities necessary to advance projects to shovel-ready status.

In 2025, we are focused on advancing the following key initiatives:

Project Kati

We are developing Project Kati in Willacy County, Texas, which is expected to be up to 166 MW of data centers for HPC, Bitcoin Hosting and other computing-intensive applications. It is co-located with a 272.6MW wind farm in Texas. We have completed the necessary studies for the ERCOT planning phase, which is the last formal step to secure approvals by regulatory agencies or grid operators, such as ERCOT in Texas, to proceed with project construction and commissioning. We have also completed the necessary amendments to the interconnection agreements with American Electric Power, the transmission service provider. We have also secured land for the project and have started capital formation activities.

Project Rosa

We are developing Project Rosa in Snyder, Texas, which is expected to be up to 187 MW of data center capacity for AI and Bitcoin Hosting and other computing-intensive applications. It will be co-located with a 242.5 MW wind farm in Texas. We have signed term sheets for both power and land purchase agreements in connection with this project.

Competition

We operate in a highly competitive sector characterized by a growing number of participants and increasing capital investment. Our approach to sourcing renewable energy focuses on curtailed or underutilized power, which is typically priced below market rates. This enables us to offer competitively priced, sustainability-aligned computing solutions.

We believe one of our key strategic advantages is our model of co-locating data centers directly with renewable power generation assets. By building behind the meter, we are able to bypass long interconnection queues and source electricity directly from the generation site. This structure not only improves power economics, but also accelerates time-to-market—an increasingly important factor for companies with large, time-sensitive computing workloads such as AI and HPC.

We believe this combination of low-cost power access, grid efficiency, and sustainability focus positions us as a differentiated provider in the digital infrastructure space.

Our emerging HPC Business competes with leading NeoCloud companies such as Crusoe, CoreWeave, Lambda, and Nebius. While these companies are much larger than we are today, we believe our competitive advantage lies in our ability to source renewable energy for the growth of this business faster and at better costs than our competitors.

Our Bitcoin Hosting Business competes with a large number of other hosting operators. We compete with public and private companies including: BitFuFu, Border, Blockstream, Blockware, Foundry, Compass Mining, Hut8, Bitdeer, and Core Scientific. Our success in our hosting operations depends on our ability to supply hosting space and power, our performance with respect to installation, operation and repair of customer equipment, our ability to obtain replacement parts, the value of our service offering to our customers and the availability of mining equipment.

Our proprietary Bitcoin MiningBusiness**** competes globally to complete new blocks and earn Bitcoin rewards.

We may compete with the following publicly traded Bitcoin mining companies: Riot Platforms, Marathon Digital Holdings, Core Scientific, Cipher Mining, Hut 8 Mining, Hive Blockchain Technologies, Bitfarms, Bitdeer Technologies Group, Cleanspark, IREN, Bit Digital, TeraWulf, and Greenidge Generation Holdings.

Key competitive factors include our number of miners, mining difficulty, operational efficiency, and the fiat value of rewards. Bitcoin mining has shifted from individual participants to large-scale, industrial facilities. Mining pools allow participants to combine processing power and share rewards based on contributed hash power. We also compete for new miners, capital, and technological advancements to enhance mining efficiency.

Many of our competitors offer more locations in more markets worldwide and have well-established international operations. Many of our competitors may have significant advantages over us, including greater name recognition, longer operating histories and higher operating margins, pre-existing relationships with current or potential customers, the capacity to provide the same or additional products and services at a lower cost, more significant marketing budgets and other financial and operational resources, more robust internal controls and systems, and better established, more extensive scale and lower cost suppliers and supplier relationships.

We face significant competition from our competitors, and we expect such competition to continue to increase, which could significantly harm our business, financial condition, and results of operations. If we cannot compete successfully against our current and future competitors, we may not be able to retain and grow our customer base, and our business and prospects may be harmed.

Intellectual Property

We seek protection for our intellectual property as appropriate. To establish and protect our proprietary rights, we rely upon a combination of patent, copyright, trade secret and trademark laws and contractual restrictions such as confidentiality agreements and intellectual property assignment agreements.

As of the date of this Annual Report, Soluna has two issued US patents, seven pending US patent applications with the U.S. Patent and Trademark Office, and 13 pending non-US patent applications. The non-US jurisdictions include Australia, Canada, China, Europe, and Japan. Among other things, concepts in these patents/patent applications generally relate to modular architecture, cooling technology, data center control, simulation, variable power consumption and local co-optimization of power generation supply with demand. Specifically, the two issued patents (US11,974,415 and US12,250,794) focus on the layout of modular data center buildings on a site, which is crucial for thermal efficiency.

We meet regularly with IP counsel to manage the portfolio and determine strategies to pursue protection of additional technologies. We maintain company policies requiring our employees, contractors, consultants and other third parties to enter into confidentiality and proprietary rights agreements to control access to our proprietary information. While there is no assurance that our pending applications will result in issued patents, we believe that our intellectual property portfolio provides us with a competitive advantage in our industry.

We also rely on trade secrets, proprietary know-how, and contractual agreements to protect our technology. However, our ability to maintain and enforce our intellectual property rights may be subject to challenges, including the risk of third-party disputes, opposition proceedings, and evolving patent laws in various jurisdictions. Loss of key patent rights or failure to obtain additional protections could adversely impact our business and competitive position.

We also hold a registered trademark for our Company name, Soluna.

We have developed a proprietary software system called MaestroOS™ to enable the automation, management, and operations of critical elements of our data centers. We have a dedicated team that engages in activities to continue to enhance the MaestroOS to drive innovation and growth in its business. MaestroOS incorporates software components licensed to the general public under open-source software licenses. We obtain many components from software developed and released by contributors to independent open-source components of our platform. Open-source licenses grant licensees broad permissions to use, copy, modify and redistribute those open-source components of our platform. As a result, open-source development and licensing practices can limit the value of our software copyright assets.

Environmental

There are increasing concerns about the quantity of carbon-intensive energy used by data centers, especially those used for Bitcoin Mining and increasingly Generative AI. We believe the integration of computing and renewable energy is the future of the modern grid.

By colocating our data centers with underutilized renewable resources, we aim to reduce the carbon footprint of our data centers and encourage renewable power plant development. An independent study done by REsurety found our data centers are 18% greener than traditional data centers. This is driven by our flexible design, our MaestroOS software platform, and our location on the grid close to renewable resources.

We participate in ERCOT emergency demand response programs, which allows the grid to redirect our power allotment back into the market during extreme weather events when needed. By taking such actions, we immediately help to stabilize the grid by allowing our power allotment to be delivered to the areas of greatest need, such as heating homes and powering hospitals. Overall, our operations incentivize the development of new renewable power generation, and they help to reduce the frequency and impact of power failures and electricity price surges.

The use of water in data centers has become a central concern in recent years. We aim to develop data centers that reduce their water consumption using the latest in direct liquid cooling technology and advanced HVAC systems that rely less on the evaporation of water.

In addition to our low-carbon execution strategy, we also monitor climate change legislation, regulation, and international treaties for any material effect on our business and the markets we serve.

Existing or Potential Governmental Regulations

Cryptocurrency mining remains largely unregulated at the federal and state levels; however, we anticipate increased regulatory attention over the near and long term. The impact of future regulatory changes on our operations is uncertain and may vary by jurisdiction.

A substantial portion of our operations, including our Project Dorothy facilities, are located in Texas, which has historically maintained a favorable regulatory environment for digital asset mining. In March 2022, ERCOT began requiring large-scale digital asset miners to apply for interconnection approval. Subsequently, in April 2022, ERCOT established a task force to develop policy recommendations for integrating large flexible loads, including Bitcoin mining operations, into the ERCOT market. This process has caused energization delays for some market participants, and we may experience similar impacts in the future.

At the federal level, regulatory momentum continues to evolve. In January 2024, the SEC approved a series of spot Bitcoin exchange-traded funds (ETFs), which have since attracted substantial investment. In February 2024, the U.S. Energy Information Administration (EIA) initiated a six-month survey to collect data on electricity usage within the cryptocurrency mining sector. The stated aim was to assess geographic growth trends and energy sourcing. Following a lawsuit, the U.S. Department of Energy suspended the survey and ordered destruction of previously collected data. Although the EIA indicated in July 2024 that it intended to restart the survey, no formal restart has occurred as of the date of this filing.

In January 2025, President Donald Trump issued an executive order establishing a presidential working group focused on regulatory clarity for digital assets, and on March 6, 2025, he signed an executive order establishing a Strategic Bitcoin Reserve and a U.S. Digital Asset Stockpile. Legislative bodies in both chambers of Congress have also announced a bipartisan working group with the stated objective of drafting comprehensive legislation to regulate digital assets, and multiple hearings have been held on the subject of fair access to financial services for digital asset companies.

Although recent regulatory signals appear favorable, the long-term trajectory of regulation remains uncertain. For example, in November 2022, the State of New York enacted legislation prohibiting new fossil fuel permits for power plants hosting proof-of-work mining, underscoring the risk of geographically targeted restrictions. While we do not operate in New York, similar measures elsewhere could materially affect our business model.

We continue to monitor evolving regulatory frameworks and potential impacts to our operations. Future legislation or rulemaking—whether related to energy consumption, environmental compliance, or digital asset classification—could have a material adverse effect on our business, financial condition, or results of operations. For additional information on regulatory risks, see the section titled “Risk Factors” in this Annual Report.

Human Capital Resources

As of December 31, 2024, we had forty-eight (48) employees, including forty-seven (47) full-time employees and one full-time consultant. Of these employees, thirteen were in finance, twenty-two in operations, two in corporate development, six in information technology and engineering, one in sales, one in human capital, one in power, and two executives. The operations personnel include both individuals directly involved in the strategy of our data centers as well as data center maintenance and supervisory roles. Certain positions within our organization require industry-specific technical knowledge. We have been successful in attracting and retaining qualified technical personnel for these positions.

None of our employees are subject to a collective bargaining agreement and we believe our relations with our employees to be positive, as reflected in our low voluntary turnover rate.

Diversity, Equity, and Inclusion

We support diversity and inclusion by ensuring a workplace where employees can thrive, and our policies are designed to promote equality and respect for everyone. Diverse backgrounds, experiences and opinions are encouraged and welcomed. In support of such diversity and inclusion, we act in accordance with our Code of Ethics and Business Conduct and our Non-Discrimination and Anti-Harassment Policy to create a safe environment free from discrimination or harassment that respects the human rights of our employees. We strive to achieve a workplace where opportunities for success are created and available for everyone equally. In support of this goal, in 2024, we required all employees to complete unconscious bias and harassment training.

Company History, Information and Organization

Soluna Holdings, Inc. (“SHI”), formerly known as Mechanical Technology, Incorporated, which was originally incorporated in the State of New York in 1961, reincorporated in the State of Nevada on March 24, 2021, and is headquartered in Albany, New York. Effective November 2, 2021, the Company changed its name from “Mechanical Technology, Incorporated” (or “MTI”) to “Soluna Holdings, Inc.” On October 29, 2021, Soluna Callisto Holdings, Inc. merged into Soluna Computing, Inc. (“SCI”), a private green data center development company and a subsidiary of SHI. MTI Instruments, Inc., a subsidiary of SHI, was sold on April 11, 2022. On March 23, 2021, our common stock commenced trading on the Nasdaq Stock Market LLC (“Nasdaq”). We formed a wholly owned subsidiary of SHI on December 31, 2023, Soluna Digital, Inc. (“Soluna Digital,” or “SDI”). Effective December 31, 2023, SCI transferred substantially all of its assets to SHI or its subsidiaries, including SDI.

Additional Information

We file or furnish periodic reports and amendments thereto, including our annual reports on Form 10-K, proxy statements, quarterly reports on Form 10-Q, current reports on Form 8-K, proxy statements and other information with the SEC. These reports, and any amendments thereto, as filed with the SEC, can be accessed, free of charge, on the SEC’s website www.sec.gov. These documents may also be accessed on our website: http://www.solunacomputing.com through a link in the “Investors” section. The contemplated documents are placed on our website as soon as practicable after their filing with the SEC. The information posted on our website is not incorporated by reference into this Annual Report.