Eleven Hydroelectric Plants in Northwest to Change Hands

The Montana Public Service Commission (MPSC) on Sept. 4 approved Northwestern Energy Corp.’s request to purchase 11 hydroelectric power plants in the state from PPL Montana for $880 million.

The plants, which comprise PPL Montana’s entire hydroelectric profile, total 630 MW of generation. Nine are run-of-river plants; the other two, the Mystic Lake Dam in Stillwater County and the Kerr Dam near Polson, are conventional storage dams. The deal also includes the Hebgen Lake reservoir, which does not have generation facilities but stores water for downstream projects.

PPL Montana’s parent company PPL Corp. announced in June that it will merge its merchant generation assets with those of Riverstone Holdings to form a new company, Talen Energy. Talen will become on of the largest independent generators in the country and will own and operate 15,320 MW of generation in Maryland, New Jersey, Texas, Massachusetts, Pennsylvania, and Montana.

A big chunk of its Montana assets, however, will be sold as part of this deal. Two coal plants will remain in the portfolio, though one, the 153-MW J. E. Corette plant near Billings, is being mothballed in 2015. PPL Montana will retain ownership of its 529 MW share of the 2,094-MW Colstrip plant east of Billings.

The deal has already received Federal Energy Regulatory Commission (FERC) approval, and once the order from the MPSC in final later this month, only a routine FERC review of the financing is necessary to close the sale.

The assets covered by the deal are the Thompson Falls Dam on the Clark Fork River; Kerr Dam on the Flathead River; Madison Dam on the Madison River; Mystic Lake Dam on West Rosebud Creek; and Hauser, Holter, Black Eagle, Rainbow, Cochrane, Ryan and Morony dams along the Missouri River, as well as Hebgen Lake.

—Thomas W. Overton is a POWER associate editor.

Photo courtesy Bill Barrett/Wikipedia