StreetLightNews

The Worcester Telegram & Gazette reports that the city council of Fitchburg, Massachusetts plans to eliminate many street lights in an effort to save money. The suggestions so far propose that either one in four street lights be turned off, or the street lights should be turned on at major intersections, and shut off at half of the remaining fixtures. No suggestion related to dimming was allegedly discussed during the meetings.

The benefits of dimming are clear and well-documented. Companies offering solutions in street light management can generate energy savings of 25-40 percent through dimming and more exact burn hours. Such a solution can typically be installed in every pole or simply in the control cabinets, the latter being the most cost-friendly solution. Therefore, dimming would be a great alternative to the suggested solutions in Fitchburg, which in practice would mean that all lights can be left turned on, thus maximizing a high level of safety for the citizens while saving energy and money at the same time.

The Canadian company, Pure-Tek Earth, has designed a solar powered LED street light where the switch, converter, controller, the wiring and the solar battery fit into a metal box that is mounted on the individual street light pole.
Pure-Tek Earth describes on their website how the solution can save thousands of dollars in electrical costs and save the world from one ton of CO2 emission per light, per year.
There is no mentioning of centralized control of the street lights, so it is unclear whether this is an option. Also, the ROI is not described, perhaps because it is unreasonably long? Equipping every single street light with both solar batteries, controllers, switches, etc. must be rather costly.

Lighting up a city’s streets is typically the single most significant energy expenditure of the city. And only few areas require the same amount of maintenance and operation resources.
With centralized control, savings of 8-10% can be achieved, but the real savings occur when the city switches to dimming. Studies and numerous experiences show that savings of 30% and above are reached, giving a pay back time of just a few years.
Follow this link to learn more about dimming technologies by e.g. power reduction and electronic ballasts.

The Danish company, Amplex, has released a report stating that savings of 25-30% have been achieved by centralizing street light control in a major Turkish city.
The report describes a pilot project where modules are installed in five control cabinets at representative locations in the city. Parts of the savings come from centralizing control, but the most significant savings are generated through dimming at off-peak hours. Two dim levels were established, and the lights went back full on early in the morning.
Even though the pilot showed savings of up to 32%, Amplex expects the savings to be even bigger when burn hours are optimized and when dimming is set earlier in e.g. industrial areas and on weekends. Additionally, savings are expected on maintenance and proactive bulb change. Based on the indications from the pilot, a very low ROI of 1-2 years can be expected.
Read the full executive report here…

The city of Ann Arbor expects to spend $640,000 on new LED street lights which are expected to pay for themselves over the next 4.2 years in energy savings.