OTTER TAIL POWER COMPANY An easy earth-friendly change to make is switching to ENERGY STAR® LEDS. LEDS use 75% less energy and last approximately 20 times longer than incandescent bulbs! Learn more at otpco.com/LEDS. in OTTER TAIL POWER COMPANY An easy earth-friendly change to make is switching to ENERGY STAR® LEDS. LEDS use 75% less energy and last approximately 20 times longer than incandescent bulbs! Learn more at otpco.com/LEDS. in