Private equity firm ArcLight Capital Partners has entered into definitive agreements to acquire 100% of the economic interests in the 484-MW Middletown Energy Center, a combined cycle natural gas power plant in Butler County, Ohio.
The firm said on July 10 that the acquisition—structured through a series of transactions with a consortium of sellers—adds a “top-quartile, highly efficient” combined cycle plant to its portfolio. Middletown, it noted, represents a strong economic opportunity within PJM Interconnection, where growing demand for firm capacity has elevated the value of modern, dispatchable assets. The transaction is expected to close in 2025, subject to regulatory approvals.
The acquisition comes amid dramatic changes in the PJM capacity landscape as the nation’s largest wholesale electricity market braces for unprecedented demand growth. In its 2025 Long-Term Load Forecast, PJM projected its summer peak load could climb by 70,000 MW to more than 220,000 MW over the next 15 years, with data centers alone accounting for nearly 32 GW of increased demand by 2030. The mounting pressure for firm generation resources was also reflected in PJM’s most recent capacity auction for the 2025–2026 delivery year, which cleared at $269.92 per megawatt-day across most of the region—an 833% increase over the previous year’s clearing price of $28.92.
Middletown: A Strategic Gas Asset in a High-Demand Market
The May 2018-opened Middletown Energy Center, located in southwestern Ohio, operates in a 1×1 combined-cycle configuration, pairing an advanced Mitsubishi Power M501GAC combustion turbine with a Vogt Power International supplementary-fired heat recovery steam generator (HRSG) and a Toshiba tandem-compound steam turbine generator. The project was developed by NTE Energy and built by Gemma Power Systems, with Sargent & Lundy providing balance-of-plant engineering. Middletown was designed alongside its sister facility—the Kings Mountain Energy Center in North Carolina—under a unified engineering and procurement model.
As POWER reported in 2019, the “replication” strategy leveraged a single 3D intelligent plant model, enabling standardized equipment specifications and streamlined procurement for both sites. Despite different climates and site requirements—Middletown required the enclosure of major OEM equipment—the approach yielded substantial schedule and cost savings. The Middletown facility’s duct-firing HRSG enables flexible output, with the steam turbine capable of producing up to 225 MW with firing and 140 MW unfired, exhausting to a TEI water-cooled condenser. The design reflects a concerted effort to optimize dispatchable efficiency while minimizing engineering risk—traits that are now increasingly valuable in PJM’s tight capacity landscape.
The facility’s ownership has undergone significant changes since its inception. Its original developer, NTE Ohio LLC, initially operating the plant from 2013 to 2020, followed by Ohio Power Partners LLC, which assumed control from 2021 to 2024. ArcLight Capital Partners’ move to acquire 100% of the plant’s economic interests means the private equity firm will gain full financial control and rights to the plant’s revenues and cash flows, effectively consolidating ownership from all previous stakeholders. The original project involved multiple financial partners, including Capital Dynamics and Wattage Finance-OH, LLC, who provided $243 million in equity commitments during the initial development phase, and a group of seven financial institutions led by BNP Paribas and Credit Agricole Corporate and Investment Banks.
Ohio Is an Emerging Data Center Hotspot
On Thursday, ArcLight highlighted Ohio’s emergence as a data center destination, which has been driven by several factors, including favorable tax policies, cooperative utilities, and robust electric grid infrastructure. DataCenterMap.com suggests the state ranks fourth in the country for its volume of data centers, after Virginia, Texas, and California.
In December 2024, Amazon Web Services announced a $10 billion investment in new data center campuses across Central Ohio, building on a previous $7.8 billion commitment from 2023 and more than $6 billion already invested through 2022, bringing the company’s total planned investment to more than $23 billion by 2030. Other major technology companies have also established significant operations in the region, including Google’s $2.3 billion investment announced in June 2024 (which adds $4.4 billion already spent since 2019) and Meta’s $800 million AI-optimized data center in Wood County announced in April 2025. Microsoft initially planned to invest $1 billion in three data center campuses in Licking County but paused these plans in April 2025.
American Electric Power’s Ohio utility, AEP Ohio, is also bracing for substantial demand growth. While the utility projects that data center electricity demand in Central Ohio will surge to 5 GW by 2030—a fivefold increase from current levels—the company in October 2024 took the unusual step of instituting a moratorium on new data center service agreements, citing unprecedented capacity constraints on its transmission and distribution networks. AEP Ohio reports that more than 50 prospective customers, primarily data center operators, have collectively requested over 30,000 megawatts of new service. On July 9, notably, the Public Utilities Commission of Ohio (PUCO) approved new tariff rules requiring large data centers to commit to paying for at least 85% of their subscribed energy use for up to 12 years, even if actual usage is lower.
“With increasing demand for digital infrastructure, Ohio has emerged as a premier hub for data centers and Middletown Energy Center, with ArcLight’s stewardship, stands ready to meet the substantial electric infrastructure needs of this vital sector,” said Angelo Acconcia, partner at ArcLight on Thursday. “This acquisition is the latest example of ArcLight’s value-add electric infrastructure investing strategy which includes power, renewables, battery storage, transmission, natural gas transmission and storage, and digital power.”
The acquisition also reflects broader trends in private equity investment in power infrastructure. Private equity firms are increasingly targeting reliable baseload power solutions that can serve the 24/7 infrastructure requirements of AI and data center operations.
ArcLight, founded in 2001, is among the most prolific infrastructure investors in the North American power sector, having owned or operated over 65 GW of generation capacity and more than 47,000 miles of electric and gas transmission infrastructure. “With its deep industry experience and suite of internal operational and technical resources, ArcLight believes it is well positioned to deliver the innovative and customized electric infrastructure solutions required by AI and data center power demand,” the company noted on Thursday. “Today, ArcLight manages the largest private power infrastructure portfolio in North America.”
—Sonal Patel is a POWER senior editor (@sonalcpatel, @POWERmagazine).