By Susan Ryba
This article appears in the July-August 2014 issue of Public Power magazine.
In 2011, Columbia Power & Water Systems in Tennessee deployed an advanced metering infrastructure system from Elster. Since then, educated guesses about system performance have been replaced by decisions built on analysis. The Tennessee utility continues to find new ways to use meter data to improve the reliability of the distribution system and deliver personalized services to customers.
CPWS staff leverage the AMI data to improve outage management, automate the distribution system, offer customers, usage data and billing options, and use interval data as the cornerstone of their engineering analysis efforts.
CPWS serves about 25,000 electric power customers, 20,000 water customers and 5,000 broadband cable TV and Internet customers. “Our opportunities to use metering data to improve our services are today limited only by our imagination and our needs,” said Karen St. Clair, assistant IT manager.
In collaboration with Hometown Connections, Elster provides AMI and integrated utilization systems to electric, gas and water utilities. These systems drive energy effi ciency, operational improvements and cost savings for utilities as well as commercial, industrial and residential customers.
Interval data collection is improving operations at CPWS. Every meter is read every day with 15-minute interval data. The utility pulls the interval data from more than 25,000 electric meters, which equals around 2.4 million records of data per day. “This tremendous amount of interval data cannot be stored indefinitely,” St. Clair said. “The solution is to summarize the data for specific customer service and engineering requirements.”
Today, customer service representatives are using the interval data to troubleshoot high bill complaints. For customers, the utility delivers usage data through a web portal. As time-of-use rates become a reality, hourly data will enable residential customers to study consumption patterns on their own.
With the system’s interval data, engineers study the performance of transformers, protective devices, circuits, breakers and substations. For example, staking engineers need to know the load on a transformer when they are drawing out service for a new account. They can see each meter’s demand and consumption on the transformer and the diversity of the load, and assign meters to a specific transformer.
The operations team needs to know that the protective devices in the field are adequately sized for the load. Staking engineers and operations need to know the profile of a circuit to monitor the loading of upstream devices. Engineering needs to know the profile of a substation breaker for peak load information, analyze load in relation to other substation breakers and compare interval data to Supervisory Control and Data Acquisition data for loss analysis. Engineers need the breaker profiles rolled up to the substation to compare substation interval data with Tennessee Valley Authority metering data, ultimately allowing for accurate and timely studies for substation growth.
“You don’t invest in an AMI system just to read meters,” St. Clair said. “AMI provides accurate data on your system that you have never had access to before. And it’s important to recognize that every utility’s situation is unique. Staff needs to compress and massage the data to meet local needs. For example, our region experienced an extreme cold snap in the winter of 2014. Our AMI system enabled us to stop high bill complaints before they happened. We used interval data to notify customers with faulty HVAC or water systems, enabling them to repair the equipment before being hit by an extraordinarily high bill at the end of the month. By helping customersavoid high utility bills, we secure a lifetime of goodwill.”
Despite the many advantages, the AMI system did not reduce the workforce at Columbia Power & Water. “The AMI deployment has expanded the skillset of our metering personnel,” St. Clair said. “We are accumulating and analyzing information about the state of our system. Employees are entering outage reports called in by customers. We are laying the groundwork for customers to report outages via smartphones, tablets, etc. The OMS system brings in data in real time from CIS, SCADA and AMI systems and displays them through the GIS system. Most importantly, we are only scratching the surface of how to use this data.”