Demand AMR Made Easy at NSTAR

By Paul DiChiara, NSTAR, and Michael Corbin, Elster Electricity

As Massachusetts’ largest investor-owned electric and gas utility, NSTAR transmits and delivers electricity and natural gas to 1.3 million customers in eastern Massachusetts.

NSTAR has approximately 315,000 electricity meters in Boston’s urban areas, with 75 percent of those meters located indoors. In downtown Boston, the percentage of indoor meters grows to more than 90 percent. Access to those indoor meters is not always available for the scheduled monthly meter reads. Also, many of the meter routes are not geographically aligned, which hampers the number of meters that can be read each day. When these demand meters are not read consistently, customers are billed based on estimated readings–or in some cases, no bill can be issued. This is a critical issue since this customer group represents more than 20 percent of NSTAR’s distribution revenue.

As an additional challenge, at the end of 2001, the Massachusetts Department of Telecommunications and Energy (DTE) directed all utilities to establish benchmarks to assess utility performance in a variety of areas related to reliability and customer service.

One of those performance benchmarks related specifically to the percentage of meters that are actually read in a normal meter reading schedule. Another DTE requirement was to reduce billing disputes caused by estimated meter readings. Because NSTAR has approximately 40,000 demand meters in the Boston area, the utility knew it would be a challenge to attain the meter reading percentage needed to meet the performance measures. NSTAR needed an automated solution for its demand meters.

The Solution

NSTAR chose Elster Electricity’s A3 ALPHA meter with Itron 50ESS ERT as the AMR solution to collect data from its demand meters. An ERT module is a radio-based end-point device that fits on electric, gas or water meters to transmit encoded consumption and tamper information from the meter. The 50ESS (electric solid state) ERT retrieves billing data directly from the A3 ALPHA meter registers and automatically transmits the data to radio-based data collection systems, including handheld reading devices, mobile AMR systems and fixed network systems. NSTAR was able to incorporate 9,500 A3 ALPHA meters with 50ESS ERT into several demand meter routes in the Boston area to meet its performance objectives for 2003.

To implement the demand meter reading system, NSTAR had to address several system requirements and issues. First, the solution needed to utilize the utility’s existing mobile AMR meter reading system and associated equipment. Both the existing customer and meter reading systems were designed with the concept of one meter being equivalent to one ERT. With the advent of the 50ESS ERT, NSTAR had to make a choice to either substantially modify its customer system or use the Itron Premierplus4 meter reading system to manage the new three-to-one ERT-to-meter relationship. NSTAR was using the Premierplus2 system at the time, but planned to migrate to the Premierplus4 system in the second quarter of 2003. By rearranging the original project schedule, NSTAR had a solution ready for implementation in September 2002.


The A3 ALPHA.Meter with 50ESS.ERT
Click here to enlarge image

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Finally, there was a self-read issue. Before the use of the new system, meters were read when the meter reader (or AMR van) went to the meter and collected the reads. The new meters “read” themselves. NSTAR then collects the data at some point after the self-read. NSTAR programs the meter with a self-read date that takes a snapshot of the energy (kWh) read, demand (kW) read and the demand reset date. These values are stored in the ERT for collection by the mobile van or handheld device.

Meeting the Challenge

NSTAR used a team approach to pull all the pieces together and address each requirement needed to make the project work. The challenge was met through a coordinated effort between meter operations (which includes the meter testing, installation and reading functions) and the billing group.

Since the requirements were to utilize NSTAR’s existing AMR meter reading vans and not have meter readers reset the peak energy demand, NSTAR paid close attention to the number of AMR demand meters being added to existing routes. To simplify the process for the long term, they decided to target one of the existing billing cycles that did not have AMR meters. By doing this, the meter reading van would only be required to do drive-by reads of AMR demand meters on that day. Because the meter technology included automatic self-reads and demand resets to store billing data, NSTAR had flexibility if meter readers were unable to complete their route on a particular day.

Next, NSTAR targeted routes that had AMR demand meters that were geographically aligned. Then they determined the bill read date of the cycle over the next few years. This date was the first self-read date that was programmed into the meter. Then NSTAR looked at the Boston area and selected two additional billing cycles that could be aligned geographically. This required a coordinated effort between the meter operations group in the Boston area and the billing group to ensure billing issues were reduced when many of the existing meters were changed to different billing cycles. Two additional meter reset dates were programmed into the meters in these cycles.

Success Realized

During the last half of 2002, NSTAR installed approximately 9,500 A3 ALPHA meters with 50ESS ERT in the three designated AMR demand meter billing cycles that were geographically aligned for this project. NSTAR saw immediate operational and business benefits from this implementation. To date, NSTAR has been able to obtain at least a 98 percent meter reading percentage from the 9,500 new meters. This is a significant increase in meter reading efficiency and has enabled NSTAR to meet its meter reading performance measures. NSTAR views the project as a success.

Paul DiChiara is manager, meter technical for NSTAR.

Michael Corbin is northeast regional sales manager for Elster Electricity.

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