ZigBee® makes energy smart


If just a fraction of all Americans knew what their electricity actually cost and used this information to adjust their power consumption accordingly, the savings would be huge, according to an article last year in the New York Times.

“Consumers would save nearly $23 billion a year if they shifted just 7 percent of their usage during peak periods to less costly times,” the newspaper wrote, citing research from Carnegie Mellon University. The article went on to say that that savings would equal the entire nation getting a free month of power every year.

Americans aren’t alone in this situation. Many people have never looked at their electricity meter and are barely aware of what electricity costs, let alone the fact that the cost of electricity can fluctuate wildly throughout a single day. Most residential energy consumers pay a flat price per hour of power, regardless of what their utility had to pay to produce that hour of power. Communicating price, and price fluctuations, can have huge benefits.

ZigBee Smart Energy is a standard, easy and affordable way for communicating energy-related information, such as price, over ZigBee wireless networks. It is a global, open standard that allows energy related devices from multiple vendors to interoperate to monitor, control and automate the use of energy. Reducing energy consumption can save consumers and their utilities a lot of money. Less energy consumption also means less environmental impact.

ZigBee Smart Energy profile is being built into many different devices. Electricity meter makers are building it into their solid state meters. Inside the home, ZigBee Smart Energy devices can range from programmable communicating thermostats and smart appliances to displays small enough to fit on a refrigerator magnet and run off a small battery. Other devices might include generic control devices for appliances such as water heaters and pool pumps, or electric and plug-in hybrid electric vehicles.

ZigBee Smart Energy supports a wide array of communications between these devices. To help consumers understand the fluctuating cost of energy, it can report multiple price tiers and price ratios in multiple currencies. It handles real time and historical information about energy consumed and energy delivered, in the case of distributed generation such as rooftop solar panels. To help consumers respond to changing energy prices, ZigBee Smart Energy supports a number of demand response and load control features. It can track multiple demand response and load control events, and audit events. Events can use multiple types of energy controls include temperature set points and offset, criticality levels (such as system emergency signals), and duty cycling. Of course, consumers can have the ability to override events initiated by the utility.

Communications for the control and billing of information must be secure. ZigBee Smart Energy supports data encryption and automatic, secure network registration using either pre-installed keys or standard public key cryptography methods. Registration can be to networks that are consumer controlled, utility controlled, or shared.

The savings from communicating the price of energy are real. At the end of 2007, Southern California Edison selected an advanced metering system that uses ZigBee to communicate price and control information. According to their business case, they are counting on that communication to produce $160 million in savings, roughly 40 percent of the system purchase price, through the reduction of peak energy consumption.

With the recent launch of the first certified ZigBee Smart Energy products from Alliance members in May, consumers and corporations will soon be able to enjoy the many benefits introduced by this technology.

For more information about ZigBee Smart Energy and new products, visit www.zigbee.org/smartenergy. You can also listen to a recorded webinar about ZigBee Smart Energy.