Automated Metering Infrastructure (AMI)
VEC has been operating its present Aclara based AMI system since 2005. The system relies on powerline carrier (PLC) signals communication to provide two-way communications between the VEC substations and meters. Data backhaul from the substation is currently provided using a mix of fiber optic cable, private carrier Ethernet, or cellular. VEC utilizes this system for 99% of demand usage metering and outage monitoring on residential, small commercial and industrial consumers.
VEC uses the National Information Solutions Cooperative (NISC) “iVUE” system to house meter data in its Meter Data Management (MDM) system. In addition, we use iVUE for billing and for VEC’s consumer interface application, SmartHub. SmartHub is a mobile and web-based application that allows members and VEC to view usage information and set alerts. This tool empowers VEC members to make changes that help them reduce their energy usage and ultimately lower their energy bill. SmartHub also provides members with a method of notifying VEC of an outage or receiving notifications from VEC.
While the cost of a residential 2S AMI meter is higher than a non-AMI meter ($40 versus $20) the benefits of fewer manual meter reads (and associated management and administrative support), increased meter reading accuracy, and outage management significantly outweigh the costs. VEC is currently able to purchase AMI meters at lower than manufacturer costs due to surplus units that have been fitted with AMI modules. However, VEC expects this supply to run out, and comparable units at full price range from $100-$160.
VEC replaces meters on a 10-year cycle or as failures occur. The advertised life expectancy is 15 years and is based on one read per day. VEC currently does three reads per day or once every 8 hours. Therefore, there is a lower life expectancy on its meters. The AMI meter communication involves a high-current pulse generated by the meter, which puts a level of stress on the AMI meters, hence shortening their life span/expectancy.
VEC is in the process of upgrading from its existing Aclara TWACS power line carrier system to a newer version called eTWACS (enhanced TWACS). eTWACS is a system that is made up of various components from the office to the substation to the service point. It utilizes a new software platform that offers improved performance and enhanced features. These enhancements include:
- Utilization of Aclara’s Fault Detection and location software to automatically detect an outage in less than 190 seconds. VEC’s current Outage Management System (OMS) requires a phone call to initiate an outage query whereas the new system will be capable of actively polling meters to determine outage status.
- Identification of momentary outage counts (also referred to as “blinks”) for each meter, a data point that is not identifiable with present system and is becoming increasingly important as more members work from home.
- 15-minute interval voltage and reactive and real power data to support system planning and develop projects to reduce outage times and system losses.