San Jose street lights get smarter

    With expectations of cutting energy costs up to 40 percent, the city unveils plan for a "smart light" system.

    By Jeffrey M. O'Brien

    How much would you guess it costs to power a city's streetlights for a year? In the case of San Jose, Calif., the tenth largest city in the country, the answer is $3.5 million. Add in the price of maintaining and replacing those lights, and that dollar figure rises much higher.

    Street lights are a great example of a wasteful, age-old system where we don't know about a failing component until it's too late. Far too much energy is expended keeping lights on when they aren't needed, and all it takes is some bird droppings on a photo sensor to make everything go kablooey.

    San Jose faces another problem, too. In the 1980's, the city replaced inefficient mercury vapor lights with low-pressure sodium bulbs, hoping both to save energy and to lessen light pollution a bit to aid astronomical research at the nearby Lick Observatory. "San Jose leaders at the time thought the overall benefit of darker skies, improved astronomical research, greater energy savings and improved lamp life was the right decisision," says San Jose director of transportation Jim Helmer. Only problem: the sodium lights are yellow -- often confusing motorists by distorting the colors of cars, curbs and stoplights, while hampering traffic cameras.

    So, as part of its so-called "Green Vision," a 15-year plan to cut per-capita energy consumption in half and derive all energy from renewable sources, San Jose announced this week a trial of smarter, more energy-efficient street lights, which will be powered by low-energy LED bulbs and monitored across a smart network.

    The 125-light test, due to launch this summer, will be implemented by hometown smart-grid company Echelon (ELON). The company is known primarily for the smart meters -- essentially, thermostats that convey real-time energy usage information to the consumer and supplier - it has deployed in various European cities.

    The streetlight network will function in a similar way to a smart electricity grid. Using the city's wi-fi network, Echelon's networking technology enables the lights to transfer real-time data about the status and performance of any given bulb. That way, maintenance crews won't have to search for a fried bulb. (For cities without a wi-fi network, Echelon's technology also works over power lines.)

    The city will be able to monitor energy consumption, anticipate outages and dim lights to save energy at the flip of a master switch.

    "LED lights consume less energy inherently. By adding control to them, putting them on a network, you can have them react intelligently," says Jeff Lund, VP of business development for Echelon. "After a sporting event or when the bars close, the lights can go up. Later that night, they can be turned down to a reduced level. If there's an emergency situation, you can have the lights flash to direct responders to the right location."

    The city is testing the system as a public appeal for Federal stimulus money. If it gets the funding, the plan is to revamp the entire 65,000-light network and, city official anticipate, reduce energy costs by 40 percent. That figure is consistent with the performance of two European cities that have implemented whole smart streetlight networks. Milton Keynes in the UK reduced energy costs by 40 percent, according to Echelon, and Oslo, Norway, slashed the cost of operating its 250,000 streetlights by 60 percent. Oslo's lights are entirely powered by hydropower, but if it were using fossil fuels to create electricity, that 60 percent savings would translate to a reduction in 1,440 tons of CO2 greenhouse gases per year.

    As cities around the country search for ways to cut their budgets in the face of dwindling tax revenue, San Jose's trial promises to be closely watched. The company has already performed proof-of-concept demos in San Francisco and Anchorage, and more are surely on their way. "The energy that goes into street lights is a big part of a city's operating costs," says Lund. "This is really about driving down costs - and providing higher quality."