Last year, Enlighted, a Sunnyvale, Calif.-based provider of lighting- and energy-management systems, began installing its light sensors into lighting fixtures at AT&T offices, garages and call centers. Currently, Enlighted has fitted them into 240 of the telecommunications provider’s facilities, amounting to just 20 percent of the firm’s 120 million square feet of real estate, according to Zach Gentry, Enlighted’s VP of business development.
AT&T’s energy savings has amounted to $8 million annually, Gentry says, noting that AT&T plans to continue rolling out Enlighted’s sensors to control lighting at all of its facilities nationwide. Once that rollout is complete, Enlighted’s system could reduce AT&T’s energy consumption by 195 gigawatt-hours—which could net the firm $200 million in cost savings over a span of 10 years.
Enlighted sensors measure motion (to determine occupancy), ambient light and indoor ambient temperature. Each sensor can monitor a 10-foot by 10-foot space and is integrated into a lighting fixture—either linking directly into an LED fixture or wired into a fluorescent fixture’s ballast, using a power pack provided by Enlighted. For AT&T, Gentry says, Enlighted installs LED fixtures as part of retrofitting projects, and deploys the sensors at the same time.
Gentry believes that the AT&T deployment (and others like it—many of which, he says, Enlighted cannot yet discuss publicly) has proven the utility of Enlighted’s Global Energy Optimization (GEO) financing model, which is designed to eliminate capital constraints as hurdles to large deployments of Enlighted’s technology. GEO is structured so that a customer pays a fee based on the amount of energy it saves, an arrangement dubbed Savings as a Service.
Under the GEO model, which is targeted at large corporations with many buildings or campuses, a company implements lighting upgrades at all of its facilities, and Enlighted installs its lighting-control system, coupled with LED lights, at no initial cost. In exchange, the customer agrees to pay, during a pre-determined timeframe, a pre-arranged rate (in cents per kilowatt-hour) for the electricity it saves thanks to Enlighted’s technology. At the conclusion of this timeframe, the customer owns the system.
“If, after the technology is installed, the customer does not pay less [than they were previously paying], then we don’t get paid,” Gentry explains.
So, for example, say a fixture uses 100 watts and the user pays its utility 10 cents per kilowatt-hour, or 10 cents every 10 hours. “In our case, every kilowatt-hour that they save, we’re going to charge them 7.5 cents,” Gentry says, as a hypothetical example. “It takes the risk of the performance outside of [the customer’s] responsibility,”
The model is similar to those used by solar and alternative power providers, which offer power purchase agreements that lock in lower rates for customers in exchange for financing for new types of energy generation.
The Enlighted sensors track ambient light and motion levels, and control each fixture’s output accordingly, in order to save energy. The sensors also send packets of data wirelessly, via the 2.4 GHz frequency band and using the IEEE 802.15.4 wireless protocol (and a proprietary mesh-style communication protocol) to the nearest Enlighted Gateway. The gateway acts as an intermediary device between the sensors and Enlighted’s Energy Manager software, which runs on a dedicated appliance at the building site, but also allows remote control—say, by a facilities manager for an entire campus of buildings—thanks to a Web-based user interface.
The software serves as a central controller for the sensors—it sends commands for lighting levels within each section of the building, based on pre-set profiles. The Energy Manager software also uses application programming interfaces to link into the building’s energy-management system, which communicates with the facility’s heating, ventilating, and air conditioning (HVAC) system. In this way, the HVAC system can make adjustments to zones within the building based on the temperature data collected by the sensors. This integration also allows Energy Manager to dim or turn off lighting in the building in accordance with a demand-response program run by the local utility provider. (Demand-response programs offer ratepayers incentives to reduce their energy consumption during times when the utility is in danger of maximizing the available energy load on the grid.)
According to Gentry, AT&T is using all of the lighting- and energy-management functions that the Enlighted system supports. However, he notes, not all of its facilities use the entire functionality.