Enlighted, the startup that’s taking an interesting node-centric approach to the networked lighting and building sensor market, announced Thursday that it has raised a $20 million Series C round of venture capital, bringing its total raised to more than $34 million since its 2009 founding.

New investor RockPort Capital led the round, and existing investors Kleiner Perkins Caufield & Byers, Draper Fisher Jurvetson and Intel Capital also took part, as did new investor DFJ JAIC, the Global DFJ Network firm focused on U.S.-Japanese opportunities.

The Sunnyvale, Calif.-based startup also announced that its sensors and software are now being employed to reduce power consumption for more than 10 million square feet of commercial building space -- double the square footage the company reported just five months ago.

That puts Enlighted in the running with such competitors as Daintree Networks, which has about 10 million square feet under its networked lights, and Adura, which had about 7 million square feet of space under its lights when it was acquired by lighting company Acuity in March.

Both these companies have raised tens of millions of dollars in VC investment, as have other smart lighting contenders like Digital Lumens and Redwood Systems. All are tackling the emerging market for networked, sensored, digitally controllable lights in different ways, and approaching the market via partnerships with both giants like Philips, Osram-Sylvania and General Electric, as well as a host of lighting installers and contractors, LED chipmakers and system integrators, and other players in the fragmented and complex lighting industry supply chain. 

Enlighted takes a slightly different tack to the smart lighting challenge than do many of its competitors, however. The core of that difference lies in the company’s decision to center a lot of its control smarts in its “Enlighted Sensor” devices, which attach to new or existing LED, fluorescent, CFL or HID light fixtures.

Unlike a typical wireless lighting network node, which tends to connect directly to lighting drivers (for LEDs) or ballasts (for fluorescent or HID lights), Enlighted’s sensors not only control lights, but also monitor light levels, temperature, occupancy and power consumption for the 100 square feet of floor space directly beneath each of them.

That means that each sensor both knows what its individual light is doing, and what it should be doing, according to Zach Gentry, vice president of marketing and product management at Enlighted. In other words, instead of relying on the vagaries of wireless networking architecture to carry data back to a central control platform, come up with preferred control options, and then send those commands back to light fixtures, Enlighted’s nodes can do most of their tasks all on their own, he said.

These lights do need a good deal of centralized support, of course, but they don’t rely on it to carry out their core functions, Gentry said. Those can include everything from dimming and brightening based on occupancy of the room or the amount of daylight that’s shining through the windows, to collecting and analyzing data to implement and manage building energy efficiency and power reduction goals, he said.

While wiring each light to a central control system could do away with networking uncertainty, it's also far more expensive than wireless options, which has limited the appeal of wireline-based systems. Enlighted does use hard-wire connections, however, he noted -- at the point where the sensor connects to the light it's installed next to, which ensures a constant communication back and forth between the two units.

Enlighted is claiming to be able to achieve a 50 percent to 75 percent reduction in lighting energy use, which is definitely on the higher end of the efficiency results we’ve seen reported from such contenders as Adura and Daintree. Gentry said the semi-autonomous nature of Enlighted’s lighting fixture sensor-controllers are one key driver of increased efficiency, compared to its competitors -- though he wouldn’t say how much more expensive it was on a per-light basis than simpler networked lighting fixture approaches.

At the same time, Enlighted is also working on using its sensor data for other things, like integrating their data with building HVAC systems to fine-tune heating and cooling, or to respond to utility demand response calls to shed power use when the grid is under stress. Part of Enlighted’s plans for its $20 million Series C round include investing in an advanced version of these types of capabilities, which it has already tested out in pilots that have been able to shave 10 percent or so from a building’s total energy usage, on top of its bigger lighting improvements.

This too is not unique -- companies like Daintree Networks and Adura have also linked occupancy sensors, thermostats and other devices into their lighting networks. But Enlighted’s decision to embed a lot of different functionality in its core node could give it a head start in tapping those kinds of features, as compared to companies that have to reach out and network disparate devices, then connect them into a smoothly functioning whole.

Watch Enlighted introduce its product: