Wireless Solutions for Demand Response Programs

by Ravi Sharma, Ember Corp.

Utilities globally will spend some $1.6 billion wirelessly linking homes to the electric grid during the next couple of years, according to industry analyst ON World. A key driver for this investment is the challenge of demand response (DR), which utilities are facing in managing consumer demand for electricity during peak-usage times.

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It’s no wonder. 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 1 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 in homes and the energy grid without building additional power plants. It’s no longer an option in many regions. The U.S. Federal Energy Policy Act of 2005, California’s Title 24 and similar initiatives in North America, Europe and Australia are driving requirements for DR systems in homes. Additionally, in December then President-elect Barack Obama announced plans to install more smart meters that monitor and decrease home energy as part of his making the United States energy efficient.

DR programs have already proven themselves in business. For example, ISO New England, a regional transmission organization, offers a demand response for business program that compensates large electricity users for reducing consumption when market prices or demand is high and system reliability is at risk. Users may choose from options designed to fit their needs based on real-time, market-pricing conditions.

Similarly, by using real-time market pricing of electricity in place of current fixed-cost pricing, DR systems should encourage energy conservation in homes, as well.

Consequently, DR needs are forging unlikely partnerships between homeowners and utilities. Utilities are deploying advanced metering infrastructure (AMI) networks to provide two-way communications between homes and utilities’ back offices via smart meters. Homeowners are adopting wireless home area networks (HANs) to gain whole-house automation and the ability to communicate with utilities in real time and better manage their energy consumption. Using wireless home automation, consumers also avoid the exorbitant cost of wiring the network of devices.

ZigBee, a global, low-power wireless networking standard designed specifically for control and monitoring applications, is usually used to tie the two networking technologies together. ZigBee-based HANs for energy management come when standards-based wireless home automation products that control entertainment, lighting, climate and security systems are showing up even in middle-class homes. ZigBee has been instrumental in driving this new wave of affordable home automation, which dovetails perfectly into HAN energy-management applications. Everyday devices and smart appliances in homes communicate with each other and utilities through gateways such as smart meters. These HAN-AMI networks enable homeowners and utilities to communicate in real time and collaboratively manage energy consumption more efficiently, especially during peak demand. They enable information exchange between consumers and utilities for things such as real-time consumption data, time-of-day pricing information, DR actions and remote-service disconnects. During peak demand, the AMI system and HAN can work together for real-time communication among consumers, businesses and utilities and automatically manage high-load devices in participating homes, such as adjusting the thermostat of an 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 rebates, and communities avoid rolling blackouts.

In the quest to urgently solve the energy dilemma, DR systems stand out for being here now. It’s proven rather than futuristic technology on the threshold 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 smart meters. On the consumer side, General Electric Co. 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 in its HomNet system for controlling home energy efficiency, security, appliances and other devices. And Boulder, Colo.,-based Tendril launched a new Web-based dashboard that records homeowners’ electricity use and tracks individual appliances to enable utilities and homeowners alike to more efficiently manage power-consuming devices.

ZigBee DR Systems in Action

Just as Wi-Fi arose to meet the demand for wireless data networking and Bluetooth for wireless cell phone headset connectivity, ZigBee is the most often used standard for wireless-monitoring and control networks. It’s designed specifically for highly reliable, low-power and low-cost applications. Similar to the way Wi-Fi specifications leverage the IEEE 802.11 standards, ZigBee is built on top of IEEE 802.15.4 radio. The devices self-assemble into wireless, mesh networks capable of organizing and healing themselves, and end nodes can operate for years on low-cost batteries.

ZigBee also has application-specific profiles to ease development and communications of devices in specific applications. In January 2008, the ZigBee Alliance unveiled the ZigBee Smart Energy public application profile specifically to support AMI and HAN devices.

AMI entails two types of networks for smart metering and energy management. A neighborhood area network (NAN) links the meters in a neighborhood, with the aggregate data from those meters being sent via cellular or satellite network back to the utility. The other is the HAN that links various monitoring and control devices in the home. An energy services portal (ESP), which could be a meter or some other device, is the gateway between the HAN and NAN.

Inside the home, the ESP communicates with a variety of devices including in-home displays (IHD), energy-management consoles and load-control devices. Load-control devices are generic plug-in devices for monitoring and controlling high-current appliances in the home.

While homeowners will not be required to participate in the DR events programs if they choose, they may be incented to participate through preferential pricing rates during peak-energy demand. Energy-usage information provided by the utility will also educate homeowners to be more aware and monitor and manage energy consumption on their own.

A Wireless No-Brainer

Integrating AMI with HANs brings the -smart in smart grid to consumers. HANs for energy management are emerging when wireless home automation products that control entertainment, lighting, climate and security systems are becoming more common. Whole-house automation systems are becoming standard in upscale homes and are beginning to make significant inroads even in modest homes as device and installation costs drop. And various broadband and wireless telecom service providers are beginning to offer home-awareness services that enable access and control of connected home systems over the Internet or cell phones. Adding energy-management capabilities was consequently a no-brainer.

Wireless networking—rather than wired technologies—slashes installation costs and allows the use of battery-powered devices not directly connected to home power lines, such as thermostats, security sensors and various remote controls and displays, to be integrated into the network. Most important, wireless can also integrate gas and water metering systems, which in any case require the use of wireless, battery-operated communications.

The needs of the utilities, the better awareness of consumers and the common pursuit of preserving the environment are accelerating adoption of wireless technology for energy management and DR.


Ravi Sharma is director of marketing for Ember Corp. He has worked in the technology industry for more than eight years. Sharma has served in various marketing roles at both start-ups and public companies, including Virtual Machine Works, IKOS Systems and Mentor Graphics. Reach him at ravi.sharma@ember.com.

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The Clarion Energy Content Team is made up of editors from various publications, including POWERGRID International, Power Engineering, Renewable Energy World, Hydro Review, Smart Energy International, and Power Engineering International. Contact the content lead for this publication at Jennifer.Runyon@ClarionEvents.com.

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