Home automation originally evolved to bring whole-house entertainment and comfort control into affluent homes. But the advent of wireless technologies combined with low-power, low-cost hardware has made home automation networks affordable and easy to install for the average homeowner. And beyond the lifestyle benefits, affordable wireless technology has also enabled manufacturers to embed wireless intelligence into a variety of energy conservation and management technologies that will have a huge impact on reducing our energy woes and greenhouse emissions in the near term.
Demand response systems for managing energy usage in homes are among the most promising of these new technologies. Households consume one-fifth of the nation's energy each year, with 60 percent of that consumption in the form of electricity. At the same time, utilities are struggling to manage the peak energy demand dilemma, where about 10 percent of electric generating capacity exists only to be used less than one percent of the time. If energy demand can respond dynamically to the available energy supply, huge cost, reliability and energy efficiency gains can be achieved within homes and the energy grid, without having to build additional power plants. In fact, it's no longer an option. The U.S. Federal Energy Policy Act of 2005, California's Title 24, and similar initiatives across North America and Europe, are driving requirements for demand response systems to be implemented in the grid and in homes.
Consequently, demand response needs are helping forge unlikely partnerships between homeowners and the electric utilities. Utilities are deploying Advanced Metering Infrastructure (AMI) networks to provide two-way communications between the home and the utilities back office via wireless smart meters. Homeowners are beginning to adopt wireless home area networks (HANs) to gain not just whole-house entertainment control but also the ability to better manage their energy consumption and this without the expense of traditional wired home automation systems.
Figure 1: A HAN includes home automation functions and can connect with a smart meter in a demand-response application.
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Tying these two networking technologies together is ZigBee, a global low-power wireless networking standard designed specifically for control and monitoring applications. ZigBee-based HANs for energy management come at a time when standards based wireless home automation products that control entertainment, lighting, climate and security systems are taking hold. ZigBee is driving this new wave of affordable home automation, so it's natural that ZigBee would dovetail perfectly into HAN energy management applications as well.
ZigBee-enables smart appliances and devices in the home to communicate with the utility through ZigBee-enabled smart-meter gateways. These HAN/AMI networks let homeowners and utilities communicate in real time and collaboratively manage energy consumption, especially during times of peak demand. They enable the collection and distribution of information to consumers and the utilities for things such as time-of-day pricing information, demand-response actions, or remote service disconnects. During periods of peak demand, for example, the AMI system and HAN can work together for better communication between consumers, businesses and utilities and even automatically manage high-load devices in participating homes, such as changing the thermostat setting of the HVAC system. Utilities save big by not having to build new power plants, which also cuts CO2 emissions. Homeowners save money through lower bills and attractive rebates. And communities avoid the ravages of rolling blackouts.
In the quest to urgently solve the nation's energy dilemma, demand response systems stand out for being here now. It's proven rather than futuristic technology, on the advent of wide scale deployment. For instance, smart meter manufacturer Itron has already announced AMI implementation plans with Southern California Edison, San Diego Gas & Electric, Detroit Edison and CenterPoint Energy in Houston, totaling more than 14 million ZigBee-enabled smart meters. On the consumer side, GE recently announced energy management-enabled appliances that can be controlled remotely by the local utility, with customers of the Louisville Gas and Electric Company. Similarly, LG Electronics Inc. has incorporated ZigBee technology from Ember in its HomNet system for controlling home energy efficiency, security, appliances and other devices. And Boulder, CO-based Tendril launched a new Web-based dashboard that records a homeowner's electricity use and tracks individual appliances to enable utilities and homeowners alike to more efficiently manage power-consuming devices.
