Contamination Mitigation May 8, 2014 Dan Greenwood Asset Management Consultant

Contamination Mitigation Agenda Contamination Events of 2011 Distribution Mitigation Efforts Impact Weather Study Cumulative Wind Vector (CWV) Leakage Current Monitoring Program

2011 Contamination Event Summary Unprecedented long term drought condition contamination related outages began April 25 th Response activities: Proactive energized and de-energized washing Elevated patrol response to momentary outages Accelerated specialized daytime corona inspections Established washing of generator leads Contamination mitigation activity tracking Contamination outage reporting

2011 Contamination Event Review Operational Opportunities: Internal Communication (Activity coordination) Resource availability (Verification of resources) 3 rd Party Facility Access (Notification processes) Mitigation Activity Tracking (Report consolidation) Program Initiation (Decision aids) ImpactWeather Study (Conditional awareness)

Contamination Mitigation Process & Procedures Distribution Contamination Process Document Detailed process with stage table as well as procedures for washing Identifies responsible individuals during process Incorporates checklists for various tasks Section that lists & defines acronyms for newer personnel Stage Number Stage NameDescription 1.1 Monitor & Analyze The procedure describes the steps taken to:  monitor the local conditions  make recommendations  initiate an inspection and / or wash 1.2 InspectThe procedures describes the steps taken to:  initiate the inspection  coordinate the inspection  perform the inspection 1.3 Wash With Inspection The procedures describes the steps taken to:  initiate the wash  coordinate the wash  perform the wash 1.4 Wash & Inspect This procedure describes the steps taken to execute a wash without a prior inspection:  initiate the wash and inspection  coordinate the wash and inspection  perform the wash and inspection 1.5 Close OutThis procedure describes the administrative task necessary to formally document the actions taken in the system of record.

Purchased Washing Trailers  Water Tank Size: 535 gallons  Gas Tank Size: 10 gallons  Max PSI: 3500 PSI  Gallons per Minute: 8 GPM

CNP Power Washing Training Purpose Why Train? Support preventative maintenance program Protect property – CNP and Public Do the job safely Learning Objectives: Operate power washer to clean energized circuit Inspect that work has been completed Minimize damage to equipment All of the above done in accordance to IEEE Standard 957 “Guide for Cleaning Insulators”

Additional Contamination Mitigation Tools Sea Spray Polymer Insulator Program Polymer insulators carry hydrophobic properties that allows moisture to bead up thus reducing tracking/leakage currents Program consists of replacing insulators during pole replacement or new pole installation Infrared Camera Inspection Program When requested by the service center particular known hot spots/critical locations are scanned Corona Camera Inspection Program Inspections performed as necessary during fall/winter and minimally performed bi-weekly during spring/summer Camera detects ionization of air surrounding an electrical field caused by a mixture of contaminants and water

ImpactWeather Study Objectives Primary focus was on comparing the total monthly contaminated line outages reported in 2011 to a set of environmental variables that included: Precipitation, temperature, dew point, humidity and wind speed What contributed to the outages of 2011 Substantially varying mean & cumulative environmental conditions Lack of appreciable rainfall Considerably higher than normal surface wind speeds Conditions near or at saturation during overnight and early morning hours  Wetting due to high levels of humidity

ImpactWeather Study Objectives Establish correlated–linear relationship between the following: Line contamination incidents Frequency and timing of natural line-washing events Environmental variables:  Wind direction - Southeast most detrimental  Wind speed - Influences rate of deposition  Daily rain fall totals which promote insulator cleaning - Greater than 0.25” per ImpactWeather promotes insulator cleaning A longer term goal of developing a model to predict probabilities of line-contamination outages

Cumulative Wind Vector (CWV) What is It? Based on Average Daily Wind Speed and Direction SE NW SW NE 180° 0° 90° 135° 270° 45°225° 315°

CWV Hypothesis Testing Back Cast Region of Susceptibility Rita Ike

CWV Hypothesis Testing Trending Analysis

Leakage Current Monitoring Initial Pilot Had to identify 4 sites One base station per site 30 sensors per site Base station & sensors within half a kilometer from each other

Leakage Current Monitoring Sensor Attachment Types Post InsulatorsSuspension Insulators

Leakage Current Monitoring Base Station Setup

Leakage Current Monitoring Objectives Short Term Is there an event underway with a high risk of flashover? Medium Term Is Washing Necessary? Can we actively predict it’s necessity? Long Term Is there Insulator Degradation?

Contamination Mitigation Lesson’s Learned & Next Steps Program Continuous Improvement Advanced preparation allows for both internal and external notifications Well established Roles and Responsibilities Matrix Ongoing review of Contamination Mitigation Program Cumulative Wind Vector (CWV) Trending Model refinement based on visual inspections to lead to decision making across various ops organizations built upon objective data Notification levels and response training Localized coastal and industrial contamination Short-term conditional forecasting based on extended weather outlook

Questions