Outdoor lighting applications, including roadway lighting and parking lot and garage lighting provide crucial services for human safety, productivity and comfort in the modern urban and suburban landscape. The installed base of roadway lighting in the United States uses an estimated 52.8 TWh of electric energy annually, while parking lot and garage lighting uses an estimated 51.1 TWh. Combined, this is the equivalent of 166.6 million barrels of oil or over
71.6 million metric tons of CO2-equivalent emissions, and also equivalent to the annual electricity use of almost 8.7 million homes. Energy Solutions estimates that the Northwest region of the U.S. uses 5.17% of national roadway and parking lighting energy, or 5.37 TWh of electricity usage and over 3.7 million metric tons of CO2-equivalent emissions annually.
This study focuses on controls systems designed for street and parking lot lighting applications. Typical lighting controls for streetlights are simple relays activated by a photocell to turn fixtures on at dusk and off at dawn. Networked controls systems available today rely on wireless radio frequency (RF) and/or power line carrier (PLC) communications technologies to network individual lighting fixtures for smarter control strategies. These systems provide tools
to manage and monitor city-wide streetlight assets remotely, including the potential to meter actual street lighting energy use. Networked controls that offer dimming capability can also provide energy savings through adaptive street lighting management, the practice of reducing lighting power and output as conditions change over time.