The eco wet-dry cooler, developed by EVAPCO, conserves water and energy used at power plants by using an innovative wet-dry fluid technology. The cooling tower works in wet-dry mode during the hot summer months and in dry mode other times of the year. In wet-dry mode, hot water is first cooled through dry coils and further cooled through additional tubes sprayed with treated water. In dry mode, the spray system is off, using no water and no water treatment chemicals. In addition, the eco wet-dry cooler has a limited visible water cloud, or condensate plume, in wet-dry mode and zero visible plume in dry mode. This technical paper presents data related to the thermal performance, water use and energy use of the pilot unit after several months of operation.