Several cities around the globe have begun replacing their regular, sodium, streetlights by low energy lamps. This way they typically save 40-50% on their city operating budgets, in some cases streets get safer and maintenance is also lower.
Take this; the total number of lamp posts in the top ten largest US cities is 4,424,361. These streetlights use an estimated 2,988,500,000 kWh of electricity annually. This produces the equivalent of 2.3 million metric tons of CO2 a year.
Now take this; using energy saving lighting easily reduces the kWh used by 50%, or savings of 1,494,250,000 kWh or 1,161,716 metric tons of CO2.
These are the findings of a recent study commissioned by the American Chamber of Commerce Executives Ford Fellowship in Regionalism and Sustainable Development.
The study examines the potential of refurbishing the streetlights in the greater Washington DC area and concludes that a 50 percent reduction in electricity would save 30.4 million kWh annually. That translates into dollar savings of $1,824,000 and a reduction in carbon footprint of 23,635 metric tons of CO2.
Washington DC might take its cue from the Smart Oslo project. Oslo, the capital of Norway, already implemented technology that converts streetlights from stand-alone lamp posts to a managed system. A company called Echelon Corporation based in San Jose (CA), has been contracted to replace Oslo’s 55,000 mechanical streetlights with “smart” electronic devices in which Echelon has engineered custom made power line communication technology.
This is where the real beauty kicks in; data from the new lamps on the Oslo streets will be collected by approximately 1,000 segment controllers, which each manage the streetlights and communicate with the City of Oslo monitoring center. The city uses internet technology to report energy consumption, traffic and weather information. The system also calculates the availability of natural light from the sun and the moon. Ultimately, the energy savings of this smart technology made will repay Oslo’s entire investment within five years.
Echelon is already reproducing the Smart Oslo project in the UK city of Milton Keynes and in Canada’s Quebec. Milton Keynes started to include over 400 streetlights as a trial project. Over the next three years 10,000 more lamp posts will be hooked on to the system. In Canada, Quebec has installed 200 streetlights in its historical district, also as part of a trial. Over the next ten years, 1,000 Quebec lamps are going to be included.
The city of Ann Arbor (MI) was among the first US cities to try out retrofit LED street lights in 2006, using a local manufacturer. LEDs is not the most efficient around, but the lighting has a nice feel to it and Ann Arbor made savings of 50% compared to the old system. A year later, the city partnered with Cree, Inc., a Durham, (NC) LED solid-state lighting components company to convert all of its downtown streetlights.
Other US cities that have refurbished their street lights are Arlington County (VA), the District of Columbia, Fairfax County (VA) and Montgomery County (MD). The researchers studying Washington DC potential savings used Fairfax County as a proxy to draw up the prognosis, including the number of streetlights per capita (0.056), cost per kWh (0.06 cents), and kWh per streetlight annually (675.5 kWh).