NSTAR Smart Grid Urban Grid Project

1. NSTAR Smart Grid Urban Grid Project July 19, 2012

2. Agenda 1 Urban Grid Monitoring & Renewables Integration 1

3. Urban Grid Monitoring & Renewables Integration Agenda • Objectives and benefits • System overview • Vendor overview • Current status • Questions

4. Program Objectives & Benefits • Enhance monitoring instrumentation on the Area 492N secondary network in Boston, Scotia St. (one of the 12 secondary network grids in downtown Boston). • Providing unprecedented visibility into the operation of the grid. • Various types of instrumentation will be deployed at grid points within manholes (major and minor nodes). • Customer AMI devices will be installed to monitor customer owned solar installations • Additional monitoring will be deployed at distribution feeders to monitor the supply side of the power flow onto the area grid. • The additional information and analysis will help increase the capability to integrate solar photovoltaics (PV) onto the secondary network, plug-in hybrids; something that is not possible today.

5. Program Objectives & Benefits • Improve system maintenance and increase the reliability of the system by proactively monitoring and correcting faults before they become major events (improved visibility into status of the urban grid both in terms of real-time information and improved understanding of the grid condition) • Results will be applicable for secondary area networks across the country.

6. Underground Instrumentation • Minor Nodes: • Sensors detect low current and high cable temperature threshold values • Equipped with an AMR type radio transmitter for monthly drive-by collection • Output from sensor collected in a waterproof communication box in manhole • After collection the instrument can be reset to be ready for the next month’s collection • Instrumentation will be used to determine underground secondary mains (cables) being open due to an open “limiter”. Monitors will be installed near the “Limiters” to detect open or overloaded conditions. • Major Nodes: • Digital Grid Technology – real time basis current sensing • Power line carrier technology is used for real time monitoring at control center.

7. Information will be collected from various points in the grid, from substations to manholes. Some information will be visible in real time, allowing an operator to monitor the conditions of assets within the network. System Overview

8. Vendor Overview Major Nodes: Digital Grid • Vendor has made sensors based on NSTAR specifications. • Will expand on existing power line carrier (PLC) system using Digital Grid sensors and relays.

9. Vendor Overview Minor Nodes: Softstuf Inc. • Currently no low cost monitoring technology exists. • NSTAR has developed and patented low cost sensor which is being manufactured by Softstuf Inc. • Sensors will provide visibility into the status of load distribution and grid asset inventory.

10. DOE: • The project was “definitized” by DOE on 10/18/2011 • A project kick-off meeting was held in May 2012 with the DOE. • All DOE project deliverables have been completed on time. Engineering: • Major Nodes • Plan: Install 52 nodes in 2012. • Construction Standard is published • Minor Nodes • Plan: Install 100 nodes in 2012. • Field Engineering received and tested 30 units prior to installation. • Manhole lookup, clean up, and Training for the UG crews are all underway. Status

11. Questions