Sun Microsystems said the network is the computer.
Nextek Power Systems says the building is the network.
The company -- which develops equipment for running data centers or appliances in conventional buildings on direct current instead of alternating current -- is working with Johnson Controls, Armstrong World Industries and others in the Emerge Alliance on a lighting system that essentially does away with wires.
Instead, low voltage DC is carried to lights through the metal grid of the building's dropped ceiling, said Liang Downey, director of digital applications at the company, during a talk at the Berkeley-Stanford Cleantech Conference, which took place in San Francisco yesterday.
As a result, installing, or moving, a light merely involves bolting it to the pre-existing ceiling structure.
“Today’s lighting infrastructure is hardwired. It is expensive to move a light fixture,” she said. With this system, “you no longer need electricians” to perform basic installation tasks.
The concept is currently being tried out at buildings at UC Berkeley, L.A. Community College, UC San Diego and a Whole Foods in Berkeley.
Nextek effectively marries two big trends: renewed interest in DC power and solid state lighting. IBM, Sun, Validus DC Systems and various universities, for instance, are experimenting with running data centers on DC to reduce power consumption and to squeeze more computing power into a finite piece of real estate.
“DC is coming. It is not a matter of if, but when,” says Jim Coakley, CEO of Power Loft Services, which builds energy efficient data centers. The Emerge Alliance exists to establish specifications and standards for DC equipment. (The guy in the picture is DC OG Thomas Edison.)
Second, the flexibility and low cost of the system provides another reason to shift to solid state lighting. LED lighting for enterprises alone will become a $1 billion business by 2014, according to a new report from Groom Energy and GTM Research.
Redwood Systems has also devised a wireless DC lighting system, but it’s slightly different. In Redwood’s scheme, AC is delivered to a central console, converted to DC, and then low voltage DC power is sent across Ethernet cables to sensors and LED lights.
The power savings in a DC world come from reducing the number of times AC has to get converted to DC and vice versa. Power from the grid and the wiring around us is made for AC. Computers, cars, ships,solarpanels, wind turbines and pretty much every device powered by batteries, however, all live in a DC world. To get to its ultimate destination, power will converted multiple times, resulting in an energy loss each time.
That heat coming from your laptop brick? The ugly love child of AC-to-DC conversion. The reduced number of components also boost reliability.
‘We are living in a DC world,” said Downey. “Everything that uses electricity internally uses DC.”
In NexTek’s case, DC current goes straight from solar panels to LEDs (which are inherently DC devices) or to a fluorescent light fixture equipped with a DC ballast. In a traditional situation, DC from solar panels would have to pass through an inverter, adding a DC to AC. Getting the power to LEDs would add require a second conversion. The equipment will also take in AC, convert it to DC and step it down in voltage before feeding it to the lights. In an sense, it's a DC microgrid inside premises originally baked for AC.
In an industrial building in Rochester, New York, delivering DC power straight from the panels to fluorescent lights improved efficiency by around 20 percent. The savings were further boosted with daylight-harvesting sensors.
But just as important, the system will cut down on the costs of remodeling and maintenance.
Side note: it was a Cal-Stanford conference, but, sadly enough, neither school brought their marching band.