THE ELECTRIC POWER RESEARCH INSTITUTE (EPRI) WILL CONDUCT A FULL-SCALE EVALUATION OF DIM, FLICKERING, AND STROBOSCOPIC ULTRAVIOLET (UV) LIGHT AS A DETERRENT TO PREVENT BAT FATALITIES AT WIND TURBINES. THE PROJECT WILL TACKLE THREE RESEARCH INTERESTS: TARGETED BEHAVIORAL RESEARCH STUDYING DETERRENT STIMULI ON BATS, IN SITU BAT DETERRENT TESTING AT A COMMERCIAL-SCALE WIND ENERGY FACILITY, AND ADVANCEMENTS FOR UV DETERRENTS. RESEARCH SUGGESTS THAT BATS BOTH SEE AND MAY BE DETERRED BY UV LIGHTS PROGRAMMED TO FLICKER ASYNCHRONOUSLY THAT PRODUCE AN IRREGULAR QUASI-VISUAL UV NOISE EFFECT (‘UV NOISE’), BUT ROBUST EVALUATION HAS NOT TAKEN PLACE AT AN OPERATIONAL, COMMERCIAL-SCALE WIND ENERGY FACILITY. EPRI WILL EVALUATE THE EFFECTIVENESS OF UV DETERRENTS ON CHANGING BAT BEHAVIOR WITHIN THE ROTOR-SWEPT ZONE USING THREE-DIMENSIONAL (3-D) FLIGHT TRACKING METHODOLOGY AND ACOUSTIC MONITORING TO TEST HOW BAT SPECIES OF CONCERN REACT AND RESPOND TO STIMULI UNDER THREE UV TREATMENTS: LIGHTS OFF (CONTROL), LIGHTS FLICKERING ASYNCHRONOUSLY (‘UV NOISE’), AND LIGHTS FLICKERING IN SYNCHRONY (‘UV FLASH’). SYNCHRONOUS FLASHING OF UV LIGHT IS A NOVEL DETERRENT STIMULUS THAT HAS NOT BEEN TESTED PREVIOUSLY AS A POTENTIAL DETERRENT. UV FLASHES MAY BE MORE NOTICEABLE AND VISUALLY DISRUPTIVE FOR BATS AT A GREATER DISTANCE THAN UV NOISE. EPRI WILL DEVELOP A CONTROLLER MECHANISM TO APPLY LIGHT TREATMENTS AS PART OF A RANDOMIZED BLOCK DESIGN. EPRI WILL VALIDATE THE EFFECTIVENESS OF NOVEL DETERRENT STIMULI/SIGNALS AND UNDERSTAND HOW BATS BEHAVE AROUND DETERRENTS.