Lights consume about 22 percent of the electricity in commercial buildings and are a huge target for waste reduction. Just think of all the lights you see left on in downtown office buildings at night. But only about 7 percent of U.S. buildings have any kind of lighting controls, creating a wide-open market for wireless technology to come in with a solution.

Daintree Networks and Adura, two startups in the wireless lighting controls field, share a lot of similarities in the way they’re attacking the problem. Both use wireless gateways and lighting fixtures to enable energy-saving strategies like turning off lights after work hours, as well as more complex tasks like linking them to occupancy sensors or natural light monitors to subtly shift lighting over time.

But the two differ on one key point. Daintree Networks, which started in 2003 as a ZigBee testing technology startup, says its ControlScope platform is end-to-end ZigBee. More specifically, it has built its existing lighting network to run a version of the low-power wireless technology meant for home automation, and has just released a gateway device certified for ZigBee’s new commercial building automation standard.

That means that Daintree’s platform should be able to connect to, and control, any other ZigBee-certified device, all the way to applications, CEO Danny Yu says. While there aren’t a lot of those devices out there yet, Daintree’s bet is that more and more lighting manufacturers, installers and contractors demanding a plug-and-play system -- and that means building to a standard, he says.

“We are the first and only truly open, interoperable lighting system,” Yu told me in an interview earlier this year. He sees the future world of lighting networks evolving in much the way that building HVAC controllers have, with proprietary technologies giving way to standards such as BACnet, LonMark and Modbus.

Adura, on the other hand, has taken the low-power wireless networking technology and adapted it in ways that extend its scalability and functionality, at the cost of rendering parts of its system more or less proprietary at the application layer.

Back in 2009, when Adura unveiled its first products, there simply wasn’t any version of ZigBee that was robust and secure enough to do what the company wanted to do, is how Adura CEO Mark Golan explained the decision.

“It’s going to take awhile for any sort of standard to emerge in commercial building lighting control,” Golan said in an interview late last year. “You’re forced to guess about what a standard will probably look like. But at the same time, you have to be functional and secure.” Even today, he said, it’s unclear whether or not all the devices that call themselves ZigBee can actually interoperate with the ease they claim.

Adura and Daintree Take Different Paths

These differences between Daintree and Adura underscores an interesting question facing the dozens of companies, from startups to lighting giants, looking at staking a claim in the wide-open smart lighting field. That’s a global market worth about 2 billion euros ($2.6 billion) today, but it’s expected to grow to about 7 billion euros ($9.1 billion) by 2020, according to an August 2011 report by McKinsey (PDF).

The question is, does the smart lighting space need standards right now, or is it too early to say? If one takes the experience of both Adura and Daintree into account, it would appear that there remains room for both paths to succeed, at least for now.

Adura has some showcase projects, including parking garages where it has cut energy use by about 40 percent, and one San Francisco office building where it has cut bills by as much as 60 percent with the right combination of occupancy sensing, daylight use and other management techniques. Last month it and other lighting companies joined Sacramento Municipal Utility District's incentive program for advanced lighting controls, which has $1 million set aside to hand out -- up to $100,000 per customer -- in energy savings rebates.

As for Daintree, it has installed lights in more than 3.5 million square feet of commercial space including offices, warehouses, retail, coldstorageand institutional settings, Yu said, and the company expects that to grow to 10 million square feet by the end of this year. Daintree’s largest customer has 10 facilities across North America being managed from a single system, and the company expects to have multiple customers with more than 25 locations apiece under management soon, he said.

Another key figure for Daintree is its list of partners -- that is, lighting systems companies and the installers and contractors that work with them to retrofit buildings. That list includes names like Cree, Albeo, Easylite, and Philips company Crescent Stonco, as well as partners that could extend its platform’s scope beyond lights. CentraLite makes occupancy sensors and plug controllers, for example.

Both Daintree and Adura team up with lighting system makers to install their controls in lights that are coming off the factory line, so more customers equals more product for them to control. Adura has installed its control nodes in lots of fluorescent lights’ ballast systems, but it has also done high-intensity discharge (HID) lights, as well as LEDs, Golan said -- though the company hasn’t disclosed which lighting companies it has worked with.

Adura is also capable of installing its controls into existing lighting infrastructures, and can actually meter power use at the device level, Golan noted. That’s an important point -- lots of otherwise “smart” lights and controls don’t accurately capture power data, making it harder to measure and prove how much energy they’re saving. Daintree, for its part, announced in January that its wireless area controllers can plug into ModBus power metering systems to capture more accurate energy data.

The Shifting Landscape of Smart Lighting

These aren’t the only two companies in the smart lighting field, of course. We’re seeing plenty of different combinations attempting to crack the market. Take Digital Lumens, which makes its own LED luminaires and networks them using ZigBee. It has been selling its systems for warehouse and cold storage retrofits with Groom Energy, and is more focused on markets where its specialized lights are needed.

Enlighted, a Sunnyvale, Calif.-based startup that includes Adura co-founder Zach Gentry, is focused on distributing more intelligence capabilities down to individual lights and sensors, to allow more fine-tuned and adaptive energy saving techniques to be deployed. Redwood Systems, a startup founded on technology to deliver both power and controls to LED lights via Ethernet cables, recently announced it is expanding to support fluorescents, HIDs and other common commercial lighting types.

We’ve also got a number of wireless technologies competing for the role of standard-of-choice for the emerging market. Dust Networks makes low-power wireless networks using the WirelessHART standard common in industrial environments, for example. Google says its Android@Home platform will include IPv6-compatible wireless networking based on the 6LoWPAN standard, though so far it’s only announced one partner, LED maker Lighting Science.

All in all, it’s a wide-open market, and neither Daintree nor Adura are blind to that fact. Both Yu and Golan mentioned that their companies were prepared to incorporate new networking standards and technologies as they’re developed, by folding them into their underlying management and control software platforms.

They’re also ready to incorporate new messages to ride across their networks. Golan and Yu told me that Adura and Daintree have both demonstrated compatibility with OpenADR, the emerging automated demand response technology for sending power-down commands from utilities to customers.

At the same time, both companies are looking at controlling lots of other things besides lights with their wireless networks, once they’re deployed. Daintree and Adura have demonstrated their ability to port sensor data to HVAC management systems, for example, using their wireless networks to carry data not specifically tied to lights. Adding heating and cooling controls, safety and security features or other systems could be next steps.

Lights, after all, are ubiquitous throughout buildings, and they’re powered by electricity, making them natural nodes for a multi-purpose network. But we’re going to have to wait a while to see just how many end devices they’ll be able to interface with -- and what standards they’re based on.