Swiss private equity firm Partners Group has agreed to acquire Middle River Power, an energy asset management platform, along with a 1.9 GW portfolio of 11 natural gas-fired power plants in California from Avenue Capital Group for $2.2bn, according to a report by Reuters.
The deal, which was announced on Tuesday, comes amid rising US power demand, driven by AI and cryptocurrency data centres, as well as increased electricity consumption for heating and transportation. With US energy consumption expected to hit record highs in 2025 and 2026, the country’s grid infrastructure is under growing strain.
Middle River Power, formed in 2016, specialises in operating and managing Avenue’s power sector investments. It also provides asset management services for 4.8 GW of third-party power plants outside California. The firm has been developing battery energy storage systems (BESS) at its gas-fired power plants, storing surplus renewable energy and releasing it when needed.
“Natural gas-fired plants and BESS are becoming increasingly critical for ensuring grid reliability,” Partners Group said in a statement.
The PE firm, which manages $150bn in global assets, sees long-term tailwinds supporting the acquisition, particularly as renewable energy penetration grows and demand for grid stability increases.
Natural gas prices have climbed 9% in 2025, recently reaching a 26-month high, partly due to record US liquefied natural gas (LNG) exports and concerns over potential declines in Canadian gas exports following tariffs imposed by US President Donald Trump.
Partners Group was advised on the transaction by Davis Polk & Wardwell, while Avenue Capital, which manages $11bn in assets, was represented by Guggenheim Securities and Morgan Stanley & Co.
