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Home Energy Magazine Online May/June 1995
Interactive Home Energy Management
Hundreds of households across the country are participating in pilot tests of interactive energy management systems, while utilities are getting a better picture of how the systems actually work in residential buildings.
One of the more closely watched tests of the technology has been conducted by American Electric Power (AEP), which plans to broaden its trial base from some 500 homes to 25,000 households in its seven-state region (Michigan, Indiana, Ohio, Virginia, Kentucky, Tennessee, and West Virginia) by the end of 1997.
The utility is using the TranstexT Advanced Energy Management (AEM) System from Integrated Communications Systems (ICS) of Atlanta. The system allows customers to automatically control central HVAC systems and appliances in response to an electric rate that reflects the utility's varying costs of producing and delivering power. The devices enable the utility to set up to four price levels per day--low, medium, high, and critical--which cover every hour of the year. In winter, for instance, a customer might choose to set the thermostat to 72°F when the price of electricity is say, 2¢/kWh (low); at 68°F when the price is 6¢/kWh (medium); at 65°F when the price is 16¢/kWh (high), and at 62°F when the price is 24¢/kWh (critical).
Customers can push a button to see the amount of electricity already used as well as the total cost for that day or for that month, and can adjust the thermostat accordingly. Joe McDonald, AEP's assistant controller and the program manager for the pilot test, said customers who have the device in their homes have saved 12%-15% on their annual electricity bills. (The system and installation generally cost less than $800.)
The system includes a TranstexT Thermostat through which customers can receive electric prices, usage, cost, and billing data and can program their central HVAC system, electric water heater, pool and spa pumps, and other appliances. The TranstexT Controller (manufactured by Johnson Controls Incorporated) operates the central HVAC system, electric water heater, and other major appliances, and is mounted near the customer's indoor heating and ventilation unit. Meanwhile, the TranstexT Major-Appliance Relay controls power to the electric water heater and other major appliances.
The system allows communications between the utility and the customer's home using the existing telephone line. The TranstexT System Manager is the software used by the utility to send and receive electric price, usage, and billing information via the device. The TranstexT Electric Meter, meanwhile, records electric use at each of the four possible price levels, can store 40 days of 15-minute interval readings, and can be read remotely.
After the thermostats for temperature settings, water heating, and small appliances have been set, customers need only enter scheduling preferences, said Tom Parker, vice president at ICS. He estimates customers can save up to 50% of their summertime cooling costs with the device.
Entergy Teams with Honeywell
Using a device from Honeywell, New Orleans-based Entergy has been conducting a small pilot program in Chenal, Arkansas, near Little Rock, with time-of-use devices made by Honeywell. Honeywell's Home and Building Control's energy management system is the result of an alliance with Oracle Corp. of Redwood Shores, California.
While somewhat similar to the system employed by AEP, Entergy plans to expand the test to 1,500 homes in the New Orleans area for households wired for fiber optics. Our biggest decision right now is whether to team with a fiber optics company, a telephone company, or even a hospital to employ time-of-use electricity management, said Entergy's Chuck Kelly.
Honeywell's system and Oracle's Media Server communicate over a network reaching into the home to a television set, allowing the customer to access information regarding utility rates and usage. Households can also access video tutorials on how to lower monthly bills, for instance by improving insulation and avoiding peak-energy periods. The server is located at the utility's service site and connects to the consumer's home via fiber optic links installed in the home.
Edison's Energy Channel
Like some other utilities, Southern California Edison has also realized that if industrial customers can use load management systems to control their electric use, residential customers can too. This spring Edison introduced its Advanced Energy Management System, (AEMS) which has already been tested in two locations. The system allows customers to view an interactive television station, the Edison Energy Channel, for information about their home's energy use.
In a pilot program, 50 households will use Edison's existing fiber optic network in combination with local telephone and cable television facilities. The system is based on CEBus (Consumer Electric Bus) technology, developed by Consumer Electronic Group of the Electronic Industrial Association. It includes a CEBus Card that allows all of the system devices to communicate with each other; a Television Video Interface Box--a computer that can process and convert digital information into TV signals (the TV will be controlled by a hand-held remote control); a universal Touch Pad--another way for consumers to interact with the system; and an Appliance CEBus Interface Module through which five appliances can be connected.
Customers will link up with Edison through SCENet, Edison's own fiber optic network, combined with cable television lines, wireless communications, or telephone lines. AEMS provides an energy profile for each of five appliances and compares energy use at any instant, or on a daily, weekly, or monthly basis. Homeowners can compare different rates offered by Edison, and participants will receive a customized bill showing how each monitored appliance contributes to the total bill. Edison officials said that with AEMS, the utility will be able to automate data collection, outage, theft detection, meter reading, and even turn service on and off. Eventually, customers will be able to choose features ranging from energy management to electronic bill payment to direct billing.
AT&T, PSE&G Team Up with Manufacturers
AT&T and Public Service Electric and Gas (PSE&G) of Newark, New Jersey, have also announced plans to develop an interactive communications system to enable utilities to provide a range of new services. The short-term plan includes automatic and remote meter reading, power outage detection at individual homes, and real-time load management, but the longer-term plan calls for giving customers flexibility through customer-controlled load management, customer-initiated what-if load calculations, bill analysis options, and other features. AT&T plans to market the system to utilities worldwide.
The system is called the AT&T Integrated Broadband Utility Solution. The basic communications protocol will follow the CEBus standards. AT&T is the overall system integrator and will develop utility interface hardware and network management software. Other partners in the venture are Intellon Corporation, a supplier of CEBus technology, and Anderson Consulting, who will develop the software interfaces between the new system and the existing utility software systems for billing, distribution management, and the like. General Electric Meter will supply the electric meters for the project, while American Meter will develop a radio-frequency interface that will capture readings from customers' gas and water meters and send those readings to AT&T's utility interface unit. Meanwhile, Honeywell is developing thermostats with customer display units that will facilitate instant two-way communication between utilities and their customers. This system is geared towards existing buildings, but for new developments, AT&T's Network Systems division is working with suppliers of home automation products to introduce HomeStar-2000, also a CEBus-based system. HomeStar-2000 would provide a variety of services, including HVAC cycling, hot water cycling, and lighting control.
AT&T plans to install Integrated Broadband Utility Solution systems in 1,000 homes by the end of 1995, and to install 10,000 systems by the end of 1996. One goal is to bring the cost of the systems to less than $500 per home by late 1996. PSE&G plans to offer the system to 500,000 customers by the year 2000.
PG&E in Venture with Microsoft
Pacific Gas & Electric (PG&E) of San Francisco, California, is teaming with Microsoft Corporation and TCI to provide residential energy information service via cable television. The system has been installed in 30 homes thus far and plans call for 1,000 homes to be hooked up this year. The communication device, provided by TCI, operates via the electric meter. The energy management unit and the set-top device, also provided by TCI, are connected to the television. Microsoft provides the operating environment which employs the familiar Windows screen on the television.
An appliance controller relay, plugged into an electrical outlet, tells the utility what appliance is operating. Using a remote control, a customer can call up tariff information--say for a heating unit--on the television screen, and then set the thermostat up or down for comfort or economy. The user has complete control of the thermostat and can override a decision made earlier.
Like other utilities, PG&E is paying for the service, the devices, and the installation during the pilot. We hope that in the future (after the trial period) the cost will be much less than the estimated $800 to $1,000 range, said Steve Phillips, project manager for the trial, which is being conducted through PG&E Enterprises. Customers will probably pay a monthly fee for the service. Eventually the service could provide households with electronic bill analysis and electronic payment. If all goes well, this could be a system we could sell to other utilities, said Phillips, echoing the sentiment of other utilities breaking ground on this new technology.