Tough Road to Getting LED Lights on the Streets
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Power plants may not spring to mind during an evening stroll on a well-lit block, or when an overhead lamp burnout darkens a treacherous bend in the road. But power plants indeed provide much of the world's nightly abundance of electric light, usually by burning fossil fuel and adding greenhouse gases to the atmosphere along with the glow. And cash-strapped cities foot the bill.
According to the Clinton Climate Initiative, street lighting accounts for a staggering 159 terawatt hours of electricity use worldwide each year. That's more than the annual output of three dozen 500-megawatt power plants. And although street lighting accounts for less than one percent of all electricity use in the United States (it's about 1.3 percent in the European Union), this comes at a hefty cost for cities. In some areas, street lights command upwards of 60 percent of municipal electricity spending.
So in tough economic times, municipalities have begun to pull the plug on inefficient lamps in favor of long-lasting, highly efficient light-emitting diode (LED) technology. In the United States, many of these projects have been supported by economic stimulus block grants for energy efficiency and conservation projects.
According to the U.S. Department of Energy, LEDs could help communities save more than $750 million per year in energy costs, while also offering benefits like more uniform light distribution. Around the world, LEDs are lighting streets from Torraca, Italy, to Toronto, Canada, and from Tianjin, China, to Sydney, Australia. Yet, in the big picture, the Clinton Climate Initiative report notes "negligible" adoption of new lighting technologies by cities. When cities do seek to cut energy costs by converting old streetlights—many of which are non-metered and owned by the local utility—they often encounter a rocky road ahead.
LED streetlights cost more up front than incumbent high-pressure sodium, mercury vapor, and metal halide lights. Partly because the technology is changing quickly, long-term performance in real-world installations is also unproven. "There are a lot of unknowns in terms of maintenance," said Ed Henderson, who runs a system of 200,000 streetlights in southeast Michigan as manager of community lighting for utility DTE Energy.
Whereas replacing a traditional streetlight in DTE’s network is typically as simple as unscrewing a dead bulb and screwing in a new one, said Henderson, LEDs can come in a variety of packages, and they're changing all the time. "Like cell phones and flat screen TVs, there's an obsolescence factor," he said. "When we put an asset up there, we want it to be up there a long, long time." The more "one-off" or specialty installations, the more difficult maintenance becomes for a utility managing streetlights on a large scale, he said.
