When President Bush signed the energy bill on August 8, he set in motion a chain of events that might lead to major changes in the way utilities price and meter retail electric services—and...
What is an Advanced Meter?
data have been available for years. For many electric utilities, the motivation to implement an AMR system has been to streamline the metering reading process and lower operating costs. Using this criteria to build the business case for implementing an AMR system, many AMR solutions were chosen based on the benefits they delivered to the electric utility. Allowing customers to participate with the utility to manage their load usage was not an issue.
Shortcomings of One-Way Communication
Much of the communications technology used for AMR systems today is one-way. These one-way systems typically consist of meters with communication modules installed. The meter reader walks by or drives by the meter and, using a handheld device, reads monthly energy consumption and in some instances demand.
If the meter is capable of collecting interval data, time-of-use (TOU) data can be calculated and presented to the consumer on a monthly basis, but there is a downside to collecting interval data in this manner. There is no audit trail to the consumer if interval data is converted to TOU data. TOU data directly from the meter provides an audit trail for the consumer to view their usage and compare with their bill. Furthermore, interval data collected on a monthly basis is no longer real-time data. It can provide a history of how energy was used in the past, but it does not provide the real-time data needed by both the utility and the energy consumer to participate in demand-response programs where energy prices can change frequently. This shortcoming of one-way communication is one reason why it is not suited for demand-response programs. It is not cost effective to make daily or hourly meter reads and a site visit is required to program the meter. The logistics and cost of frequent site visits to reprogram the meter for dynamically changing TOU rates would be prohibitive.
Intelligent Two-Way Communications
Some AMR systems on the market today have state-of-the-art two-way communications that make them well suited for demand-response programs. These systems are affordable, scalable, and robust.
One two-way communication system available today uses standard wide area network (WAN) communications such as landline or cellular telephone to communicate with area data collectors. The data collectors manage a local area network (LAN) of meters that use unlicensed 900 MHz radio frequency (RF) technology. The 900 MHz communications technology provides full two-way communication to every end-point meter.
The system is robust because all meters on the 900 MHz LAN can function as repeaters. This greatly expands the coverage area of the communication network around a data collector and lessens system capital cost, lowers maintenance, and reduces communication expenses. Additionally, this two-way communication network is self-healing. If local RF conditions change and a meter can no longer communicate with its data collector, the meter automatically registers itself on the network through an alternate path or through another data collector. Since this system uses two-way spread spectrum frequency hopping technology, meters are self-registering. Network expansion is reduced to the simple task of installing a meter. The installed meter automatically registers with the area data