Managing Energy with Swarm Logic

Self-organizing equipment could cut energy bills.

Air-conditioning units and heating systems are examples of power-hungry equipment that regularly switches on and off in commercial buildings. When these devices are all switched on at once, power consumption spikes, and a building's owners are left with hefty peak-demand charges on their electricity bills.

Smart switch: The controller shown here could improve the energy efficiency of building appliances. The devices communicate wirelessly and use swarming algorithms to collaboratively decide how to manage power usage. Credit: REGEN Energy

A startup based in Toronto says that it has come up with a way to reduce energy use by mimicking the self-organizing behavior of bees. REGEN Energy has developed a wireless controller that connects to the control box on a piece of building equipment and functions as a smart power switch. Once several controllers have been activated, they detect each other using a networking standard called ZigBee and begin negotiating the best times to turn equipment on and off. The devices learn the power cycles of each appliance and reconfigure them to maximize collective efficiency.

The goal is to avoid everything coming on at the same time without sacrificing individual performance. The devices work through this problem using a "swarm algorithm" that coordinates activity without any single device issuing orders.

"Every node thinks for itself," says Mark Kerbel, cofounder and chief executive officer of REGEN Energy, which invented the proprietary algorithm embedded in each device. Before making a decision, he explains, a node will consider the circumstances of other nodes in its network. For example, if a refrigerator needs to cycle on to maintain a minimum temperature, a node connected to a fan or pump will stay off for an extra 15 minutes to keep power use below a certain threshold. "The devices must satisfy the local restraint but simultaneously satisfy the system objective," says Kerbel, adding that a typical building might have between 10 and 40 controllers working together in a single "hive." The devices are simple and quick to install and, because there's no human intervention, require no special training to use.

It's a dramatic departure from the top-down command model associated with current building-automation systems. Some researchers say that the decentralized approach to energy management offers a cheaper, more effective way to manage supply and demand in a delicately balanced electricity system. Indeed, some believe that it could be an early prescription for an emerging smart grid.

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"You're seeing a lot more interest in this on a modest scale," says David Chassin, a scientist at Pacific Northwest National Laboratory's energy-technology group, which is heading up the GridWise smart-grid initiative.

The benefits could extend beyond electricity savings for building owners. Today's electricity system is designed for peak consumption, which means that power plants are built to satisfy those few minutes of each day when power demand surges well above daily averages. By reducing peak demand on a large scale, utilities can maximize the operation of existing power plants while reducing the need to build new plants for occasional use. Another potential benefit is reduced carbon emissions, since power plants that supply peak electricity tend to be less efficient and fueled by coal and natural gas.