Smart systems: Conserving energy with automation

We are all aware that the North American energy grid is under stress, and utilities urgently need to manage peak versus off-peak energy demand to reduce the need to build new power plants. One of the ways power-generating companies are deferring the large investment of new plants is through the use of automation – in particular, through Advanced Metering Infrastructure (AMI), which combines Home Area Networks (HANs) and Neighbourhood Area Networks (NANs) as part of the overall Smart Grid initiative.

This infrastructure allows utilities to send and receive information and commands to and from your home for multiple purposes, including time-of-use pricing, demand response actions and even remote disconnects to, for example, remove your air conditioner from the grid if the system is being overtaxed. The Home Area Networks include such items as thermostats, load switches, lighting systems and the local energy meter. Neighbourhood networks will aggregate information from up to several thousand Home Area Networks using mesh technology to backhaul all of this information to the utility’s central control facility.

The smart meter will, in most cases, also serve as the Home Area Network gateway to all of the enabled devices in the home.

A number of reports on ZigBee and Smart Grid devices have recently been released, including one from GE that anticipates volumes such as 750 million to one billion smart connected devices in the U.S. by 2017. In 2007, ZigBee made up 75 percent of the IEEE 802.15.4 chipset units installed in the world, which equates to numbers like 40-plus million meters deployed over the next few years, and a total potential market of 1.5 billion devices in the near term. Market researchers ON World estimate that utilities will spend $1.6 billion US on wireless sensor network technologies – predominantly ZigBee – for smart metering and demand response by the end of this year.

To meet all of the different demands placed on the protocol, ZigBee has defined three distinct network stacks, each targeted at a unique though somewhat overlapping market – ZigBee PRO, ZigBee RF4CE and ZigBee IP for the Smart Energy 2.0 specification, a 244-page document available on their website.

The average ZigBee system consumes only 0.39 watts per day, while a Wi-Fi system requires approximately 0.87 watts over the same period, which is why ZigBee is so well-suited to “passive” devices such as the nodes in a Home Area Network. Since the new Smart Grid 2.0 specification is IP-based, it will be easier to integrate with Wi-Fi for broader distribution, and to interface with other plugged-in devices in the home.

This is why the ZigBee and Wi-Fi Alliance have announced plans to collaborate on wireless Home Area Networks for Smart Grid applications. The joint effort looks to extend the opportunity for interoperable wireless technology in the smart home by merging Wi-Fi’s communication technology with ZigBee Smart Energy 2.0, the standard on which all Home Area Networks are based. The agreement between the two alliances will integrate the two communication technologies in a smart home environment.

I have a friend in Perth, Australia who has been manually managing his energy demand for years by only running his heat and water pumps to charge his water system at off-peak hours. All he did was put a keyed switch by his front entrance to turn the unit on in the evenings and off during the day when no one was home. This is the same idea as setting back thermostats in our houses, which is just the beginning.

In Gothenburg, Sweden, they are deploying a ZigBee-based network to 270,000 homes, and in the process plan to save millions of Euros by eliminating the manual meter reading and billing actual usage to customers.

Various broadband and wireless telecom service providers are beginning to offer “home awareness” services that can access and control connected home systems over the Internet or cell phone. So when you are out and about wondering if you turned off the stove in the future, you will be able to say, “We have an app for that!”

Ian Verhappen, P.Eng. is an ISA Fellow, ISA Certified Automation Professional, and a recognized authority on Foundation Fieldbus and industrial communications technologies. Verhappen operates a global consultancy, Industrial Automation Networks Inc., specializing in field level industrial communications, process analytics and heavy oil / oil sands automation. Feedback is always welcome via e-mail at iverhappen@gmail.com.