Networked street lights are a fascinating space where the latest in city-scale, energyefficient lighting and digital networking combine. We’ve seen a ton of new entrants into the field, from smart meter players like Sensus, Silver Spring Networks (SSNI) and ABB’s Tropos Networks adding streetlights to their mix of networked end-points, to LED contenders working with cities and contractors to tap the extra efficiency and functionality inherent in those digital sources of light.

On Wednesday, lighting giant and Siemens subsidiary (and would-be spinoff) Osram announced it was launching its own networked street lighting solution, using technology from San Jose, Calif.-based networked street lighting stalwart Echelon (ELON). The Osram-Echelon combo promises to squeeze up to 40 percent more energy efficiency out of a city or utility street light system, compared to just using high-efficiency lamps alone.

For Echelon, it’s a big new partner for a powerline carrier (PLC) technology that’s been connecting streetlights to central control systems for more than a decade. Echelon’s system connects about 1 million street lights around the world, running city lighting networks in locations from Anchorage, Alaska to Oslo, Norway, and points in between. In China alone, the company is hoping to install 500,000 smart street lights by 2014.

Echelon has been working with Philips on networked street lighting for some time, as well as many other smaller partners in the complicated lighting industry chain, Varun Nagaraj, Echelon’s senior vice president and general manager, told me in a Wednesday interview.

In the case of Osram, Echelon will be building its control chipsets into Osram’s lighting ballasts, drivers and controllers, both for high-efficiency, modern LED replacements and for existing induction-lighting luminaires, as well as supplying the networking controllers and underlying standards-based communications, he said.

In general, Echelon claims that its networked lighting system can squeeze about 30 percent out of energy use of existing streetlight systems, as well as drive a 20 percent reduction in operations and maintenance costs through more visibility into the assets and how they’re operating.

The vast majority of the world’s streetlights remain both dumb and inefficient. At most, some more modern streetlights will have photocells that track the rise and fall of the sun to turn lights on and off, Nagaraj said. Without a network, however, there’s no way to tell whether they’re still working or have broken down, resulting in certain lights being inadvertently left on all day -- so-called “dayburners.”

Connecting them to a network can offer real-time control of whatever functionality the light itself offers. That’s not much for old-style high-pressure sodium and metal halide streetlights, which can take minutes or hours to “warm up” from dark to fully lit.

LEDs, on the other hand, can dim themselves to various mid-points to save energy, brighten, or blink on and off to guide police and paramedics to the scene of an accident or a crime -- many city LED streetlight projects have been centered around public safety.

Given all that extra functionality, it almost doesn’t make sense to install LED street lights on their own, without adding some basic networking, Nagaraj said. A general rule of thumb is that street lighting networks can pay for themselves in energy savings in markets where electricity costs about 15 cents per kilowatt-hour or more, which is typical in Europe and some of the more expensive markets in the United States.

In places where power isn’t that expensive, cities or utilities can still capture return on investment from ongoing operations and maintenance improvements, he added. Having sensors connected to your streetlights also allows you to collect data on energy use over time, both for operations and budgeting purposes and for preventative maintenance and predictive replacement. That’s an important longer-term benefit that adds up over the decades-long lifespan of each new luminaire, both in reduced costs and reduced employee-hours spent and fuel burned on emergency truck rolls.

Street lights have also been a focus of the early adoption of LEDs, since cities can afford to finance upgrades to lights they’re going to own for a long time, making their upfront cost easier to justify. Even so, most cities are looking for financing partners to take a role in both the replacement and ongoing operations of smart streetlight networks, either via energy services (ESCO) models in the U.S. and Europe, or in China, a “concession” model in which private companies actually buy and own city streetlight networks, Nagaraj said.

As for Osram, it clearly has an interest in that market and in partnerships with contractors and ESCOs that befit its role as one of the world’s biggest lighting companies. Competitors include players like Philips and General Electric, as well as smaller contenders like Bridgelux, which is working with Chevron Energy Solutions on a smart LED street light offering, and Cree, which is installing streetlights for cities via its acquisition of Ruud Lighting and its outdoor LED subsidiary BetaLED.

Wednesday’s announcement didn’t name any specific projects or customers for the new street-lighting solution. However, Siemens and Echelon have been working together on the smart grid front -- in October, they announced plans to integrate Echelon’s smart grid control operating system with the EnergyIP smart grid data management platform from eMeter, the MDM provider that Siemens bought in December 2011.