Traditional techniques such as adding insulation or window caulk can make buildings more energy efficient, but those strategies go only so far in reducing energy bills. Smart building systems linked to the smart grid offer a more comprehensive way to reduce consumption.
One company that has invested heavily in smart buildings is Schneider Electric, a 174-year-old French conglomerate that makes software and hardware for energy-efficient buildings. To test its own products, the company built a new headquarters campus near La Défense, the Parisian business district. Known as “Le Hive,” the collection of interconnected buildings is a test bed for advanced sensor, measurement, analysis, and control technologies that promise to reduce the electricity bill for Schneider while proving to potential customers how powerful the technologies are.
Le Hive opened at the end of 2008, and it now holds more than 1,700 employees. There are no special energy-efficiency tricks embedded in the design of the building—it is typical of most new construction in Europe. The company wanted to use building systems to reduce energy consumption and not depend on expensive construction techniques that most building owners couldn’t afford.
Schneider’s goals for its headquarters were straightforward. The average electricity consumption of an office building in Paris is 400 kilowatt-hours per square meter per year. The European Union has directed that all buildings reduce consumption to 50 kilowatt-hours per square meter per year by 2030. Le Hive was meant to demonstrate that the path toward that goal can be quick and relatively painless. The company has reduced its headquarters’ energy consumption from more than 300 kilowatt-hours per square meter to 65.
The Schneider system, dubbed EcoStruxure, started by collecting and analyzing data on the building’s energy consumption patterns. Then a series of software and hardware components were installed, all of which can be controlled from a single interface such as a laptop or smart phone. In other words, the heating system, the air-conditioning system, the lighting management system, the security system, the fire control system, the surveillance system, the IT system, and the ventilation system (all of which used to be discrete systems with separate controls and dedicated technicians and managers) are all integrated into a single comprehensive building management system with a single point of control.
Next, RFID cards were distributed to every employee. Each card alerts a sensor system to where the employee is and adjusts the lighting and HVAC systems accordingly. A worker leaves his office for lunch, for instance, and the lights and air-conditioner in that office turn off immediately. He returns and the comfort settings he has requested kick right in. Other sensors turn the artificial lighting up or down in accordance with the available sunlight. Similarly, an automated window shading system adjusts itself in calibration with the cooling, heating, and lighting needs. If the blinds are open and sunlight is streaming in, then the lighting system dims by just the right amount to maintain a consistent environment.
Schneider’s system can’t cut energy usage for every commercial building as well as it did in Le Hive. But the company does claim that it can reduce energy bills by an average of 30 percent. “It’s much more difficult to get from 65 [kilowatt-hours] to 50 than it is to get from 100 to 65,” says Pierre Tabary, Schneider Electric’s vice president of educational buildings and office buildings. “All the low-hanging fruit is gone.” But Schneider isn’t out of ideas. The next segment to tackle is in IT—computers and monitors plugged into wall sockets. The company hopes to eventually link that load to the control system so that employees’ PCs turn off automatically when they leave the room for extended periods.
Another plan is to introduce personalized energy dashboards for all building occupants so that each office worker, not just the facilities manager, will see energy consumption patterns in specific zones of the building. It is assumed that such information will encourage employees to reduce their individual energy use, assuming that their own comfort isn’t compromised.
Le Hive is a glimpse into the future of smart buildings. Schneider Electric is probably saving about 150,000 euros a year by reducing energy consumption at its headquarters from more than 300 kilowatt-hours per square meter to 65; at that rate the system would pay for itself within about three years. (The company wouldn’t share cost figures for the project, so the estimate comes from typical building automation and security costs of 10 euros per square meter, with a 25 percent premium built in for the extra features like the RFID security system.) While Schneider’s EcoStruxure can’t perform these wonders for every commercial building, the company does claim that it can reduce energy bills by an average of 30 percent for most clients, and by as much as 70 percent for some.
Sam Jaffe is a research manager for IDC Energy Insights.