Presented by: Keith Gray & Julienne Sugarek CenterPoint Energy Cable Life Extension Presented by: Keith Gray & Julienne Sugarek CenterPoint Energy

Overview Introduction Challenge Solution Benefits

Who Is CenterPoint Energy? Natural gas sales and delivery Over 3.2 million residential, commercial and industrial customers in six states Competitive gas services (CES) Over 11,100 commercial, industrial and wholesale customers across central U.S. Electric transmission and distribution Over 2.3 million meters in the Houston area 5,000+ square mile electric service territory

Underground Residential Distribution System 18,000+ URD loops 13,000+ miles of cable Pad-mounted transformers, secondary pedestals, primary pull holes, terminal poles, terminators, elbows and other equipment

Challenge

Challenge

Challenge Wholesale replacement of all aged loops is too expensive and requires too many resources What Do We Do?

Solution Assessment On-site mitigations Warranty Operational Issues

Solution - Assessment Needed a better understanding of what was causing failures and the condition of our cable: Voids such as insulation cuts, overheating Stress enhancements such as cut back issues, foreign objects, contaminants

Solution - Assessment Off-line assessment creates a controlled environment by eliminating outside noise and interference Requires isolation of the span being assessed The evaluation is consistent with manufacturer standards for cable (ANSI/ICEA S-97-682), terminations (IEEE48) and connectors (IEEE386) Provides a strategic view into the condition of our cables Assessment results assist with prioritization for future rehabilitation activity

2. Assessment Equipment Connected Solution - Assessment 2. Assessment Equipment Connected 1. Span Isolated 3. Assessment Performed

Solution – On-site Mitigations As part of the assessment, a full loop inspection is performed 99.6% of loops required mitigation More than 70% of issues are addressed on-site Assessment enables technicians to pinpoint and address where mitigations are required

Solution – On-site Mitigations Sub standard PD – Stress cone / Term Removed Stress Cone, prep for extended semi-cone QTIII cold shrink termination installed Tested and Met Standards

Solution – On-site Mitigations New Elbow Installed Tested and Met Standards No Stress Relief Overlap Knife Cuts in Insulation Insulation Repaired

Solution - Warranty All assessed spans are given a 15-year performance guarantee Guarantee is a credit per span and per failure Length of the guarantee depends on the cable type

Solution – Refinements A number of operational issues were overcome after the initial roll out: Failure rate was 51% On site mitigation performance Crew structuring and hours worked

Benefits Broader reach at a reduced cost and uses fewer resources Formerly CNP would address 35 loops per year, now we address 500+ per year Costs are more predictable Resource requirements are more predictable A capital program that results in O&M savings

Benefits Younger Loops Older Loops No PSR Required PSR Required Tested & Older than 1985 All Loops All Tested

Benefits A critical step is developing the financial model to demonstrate the cost avoidance “Outages avoided per year” ratio developed based on pre-program and post-program outage data Apply to number of loops evaluated and multiply by the average cost of a reactive URD outage to estimate the cost avoidance

Summary Aging infrastructure is a real issue in our industry In order to address it, we have to be innovative to ensure we are maximizing our investments A critical success factor is developing a model that uses real data to illustrate the benefits realized