Burnt coils inside unit 4 at the Hartwell Power Plant were discovered during a scheduled biennial outage that began in May 2016. Layers of damaged coils were removed, stripped of insulation, re-soldered, and reinsulated during installation repairs done by maintenance workers on site. Because the work was completed in-house, about $44,000 in final costs circumvented more than $4 million in potential costs. Savings were calculated on the basis of probable failure in the event issues weren’t identified and addressed immediately, according to Ryan Hanna, a Hartwell Power Plant hydropower manager.