Tempe, Arizona is embarking on phase one of a street-light-retrofit project and has chosen induction lights rather than LED-based solid-state lighting (SSL) to replace high-pressure-sodium (HPS) and metal-halide (MH) sources. US Lighting Tech (USLT) announced that it will supply 1000 induction lights to the city saving as much as 40% of the energy required to power the lights.
Apparently, the city decided that LEDs aren’t a good match for the temperature extremes of the desert southwest climate. Alexander Ham, Vice President of Operations for USLT said, “After evaluating the two leading street lighting platforms of induction and light emitting diode, or LED, Tempe ruled out LED for its high equipment cost and performance volatility in the temperature extremes of the southern Arizona environment.”
Certainly other municipalities and utilities have made a case for induction lights over SSL – mainly due to lower upfront costs. It remains to be seen if the temperature issue will be a real roadblock for LEDs. It’s well known that luminaire designs must efficiently conduct heat away from LEDs for reliable operation. But LEDs are certainly performing reliably in higher-ambient-temperature environments than the southwest desert night.
Still induction lighting does offer energy savings over legacy technologies. USLT will supply 70W Cobra 100 Series lights to Tempe, in general replacing 125W HPS or MH lights. Induction lights do not offer the fine-grain dimming capability that LEDs can achieve to enhance savings through adaptive controls.
Columbus, Ohio reports bad LED experience
Generally LED street lights are getting rave reviews for everything except upfront costs, but the city of Columbus, Ohio also reported issues with a test of LED street lights according to The Columbus Dispatch. The newspaper reported that some of the energy-efficient lights tested failed within two months of installation.
In actuality, the public utilities spokesperson didn’t specifically detail the problems in a test that included LED and induction lights. Certainly most other municipalities and utilities have had quite a different experience. The utility also said that the lights afforded only 20% in energy savings, so the city will stick with legacy lights for now.
Nearby Dublin, Ohio meanwhile, has banked $500,000 to begin a retrofit of 1500 street lights with LED technology. That city’s testing has shown the LED lights to use 40 to 50% less energy.
Iowa and Mississippi update
The move to LED street and area lights continues to happen in many parts of the US. The Des Moines Register reports that the Iowa city is installing LED-based area lighting in a local Valley Junction park. The city will install the lights this fall looking for 50% energy savings. Moreover, the city will use the project as a pilot that could lead to a retrofit of all of the period lighting in Valley Junction.
In Rankin County, Mississippi the city of Flowood has installed solar-powered LED street lights according to The Clarion Ledger. Also on the solar LED front, the Consortium for Solar Lighting published its first recommended practices document.
