It will provide back-up supplies for the Lanark and Galloway hydro schemes which date back decades.
Up to 350 job roles could be at risk at Selby-based Drax Group, which operates in the UK and USA.
The site at Glenlee in Dumfries and Galloway has been operating for the best part of a century.
Fifteen people are cleared of planning to lock themselves to objects during climate protest.
They would provide back-up power for eight stations in the historic Galloway and Lanark schemes.
Drax, whose Selby site provides 5% of UK electricity, failed to give "robust" data, a watchdog says.
Work around the Tongland Dam in Galloway hopes to try to address a 90% drop in fish numbers.
Drax Power Limited says it received a tip-off about a planned protest camp and sought protection.
Union bosses have praised Drax canteen workers' refusal to back down on pay as "an inspiration."
