The fittings are manufactured locally by Global Green Lighting (GGL) and supplied with wireless connectivity by Sensus. Sensus’ FlexNet technology allows officials to monitor and control all of the city’s streetlights from a single location.
The city replaced existing sodium fixtures with 26,000 induction and LED lamps preconfigured with FlexNet wireless endpoints over a 16-month period. The on-board, utility-certified meter measures and reports the energy savings on a monthly basis. The streetlights use the city’s wireless infrastructure hosted by the municipality’s Electric Power Board’s fibre optics network to manage the power consumption.
‘Utilising the city-wide fibre optics network that was installed for the primary purpose of smart grid meter management, the city has experienced much economic success by attracting new manufacturing such as Volkswagen, and Amazon,’ Don Lepard, founder and president of Global Green Lighting, told Lux Review.
‘GGL is using the fibre optic system that is located on the same poles as the lights to back haul a unlimited amount of smart city devices, Wifi, and even small cell LTE transmitters.’
A total of 1,908 decorative LED post-top luminaires were installed, each consuming 135W; almost 20,000 140W LED lanterns and over 5,000 250W LED lanterns were also installed. All are dimmable.
Energy consumption has been reduced by 72 per cent and light output has doubled.
‘Not only will the new lighting save energy and maintenance cost, but to also make the environment safer, it will become the host for the next generation of wireless networking at the same time,’ Lepard said.
He added: ‘GGL has partnered with a smart grid metering company to create the world’s first advanced lighting control system with metering that is certified by the local power utility with the capabilities of measuring and reporting the energy savings directly to the monthly energy billing for an instant response to energy conservation.’
The advanced metering infrastructure provides two-way communication between the smart meter and the utility or third-party. An online mapping system allows maintenance teams to monitor the lighting across the city, and instantly pinpoint any problems. If any lantern stops functioning correctly, an alarm is established and work order issued within 15 seconds automatically. The alarms will remain open until cleared.
‘Once installed,’ Lepard continued, ‘the light itself has a multipurpose. Firstly, better light while saving a reported 72 per cent on energy and 75 per cent on maintenance; secondly, to host the patented GGL design with a power over Ethernet to give high speed internet connection and power to other smart city devices, such as sensors, HD cameras, Wi-Fi and small cell transmitters.’
The lighting can be controlled all together, in groups or in isolation. Profiles are established for each lantern, detailing the vitals of each unit and including predictions of when the light will need to be replaced.
After midnight, the city’s lighting automatically dims to 25 per cent to save energy. In an emergency, an override button allows lights to be ramped back up to 100 per cent or even flash.
‘The Chattanooga program has clearly shown the remarkable efficiencies gained by retrofitting municipal lighting,’ concludes Charlie Nobles of Sensus.