Private equity firm Hull Street Energy (HSE) has completed the acquisition of two US peaking power generation facilities with a combined capacity of 1.26GW from Rockland Capital.

The transaction brings the 677MW Lee County Generating Station in Illinois and the 586MW Tait Electric Generating Station in Ohio into HSE’s thermal power generation platform, Milepost Power.

Funding for the deal included equity from HSE-managed funds along with senior secured debt financing.

The acquired sites make up the GridFlex Portfolio. The Lee County Generating Station is a natural gas turbine facility.

The Tait Electric Generating Station operates as a dual-fuel power plant.

Both facilities are situated within the Pennsylvania-Jersey-Maryland (PJM) electricity market, providing additional capacity and flexibility in response to changing demand and supply patterns.

According to HSE, these resources play a key role in supporting grid reliability in the PJM region.

Hull Street Energy founder and managing partner Sarah Wright said: “Dispatchable resources are increasingly important as the resource mix becomes more intermittent and demand grows. This is particularly true in PJM where declining reserve margins are increasing the need to retain and improve assets like Lee and Tait.”

Following the acquisition, Milepost Power’s fleet comprises nearly 5GW of gas-fired and dual-fuel generation capacity.

The financing for the transaction was arranged with Santander and Investec as joint lead arrangers and joint bookrunners, with Santander serving as administrative agent.

Troutman Pepper Locke advised HSE on legal matters, while PEI Global Partners and Houlihan Lokey served as financial advisers. Bracewell provided legal counsel to Rockland.

HSE first announced its intention to acquire the facilities in March 2026.

In May, HSE signed an agreement to acquire clean energy producer FirstLight USA from the Public Sector Pension Investment Board.

The transaction covers a portfolio of nearly 1.4GW of electricity generation assets in the north-east of the US. These include Northfield Mountain, a 1.17GW pumped storage hydro facility in Massachusetts, as well as 14 hydroelectric stations in Connecticut, Massachusetts and Pennsylvania, and three operational solar and battery facilities in the region.