Atlantic Power has agreed to acquire equity ownership interests in two contracted biomass plants in North Carolina and Michigan, US.

The shares will be purchased from AltaGas Power Holdings US for $20m. Atlantic Power will use its discretionary cash to fund the transaction.

Located in North Carolina, the 48MW Craven County Wood Energy biomass plant has been in service since October 1990.

Atlantic Power will acquire a 50% interest from AltaGas, while the remaining 50% interest will remain with CMS Energy.

Additionally, Craven County has a power purchase agreement (PPA) with Duke Energy Carolinas that runs through December 2027.

Grayling Generating Station is also a biomass plant in Michigan with 37MW power generating capacity. It has been in service since June 1992.

Under the deal, Atlantic Power will acquire a 30% interest in the plant from AltaGas and the remaining will be held by Fortistar (20%) and CMS Energy (50%).

Grayling also has a PPA with Consumers Energy, a utility subsidiary of CMS Energy, which runs through December 2027.

Atlantic Power president and CEO James J Moore said: “Since last summer, we have announced the acquisitions of five plants, Craven County and Grayling; the remaining ownership interests in the Koma Kulshan hydro facility, which we acquired in July; and the Allendale and Dorchester biomass plants in South Carolina, on which we expect to close later this year.

“The PPA for these acquired plants run through December 2027, March 2037 and October 2043, respectively.”

Completion of the deal is subject to the approval of the US Federal Energy Regulatory Commission and customary third-party consents.