Optimizing Circuit Performance Through Data Collection Richard Colunga May 4, 2017 This presentation is being provided for informational purposes only and does not purport to be comprehensive. Neither CenterPoint Energy, Inc., together with its subsidiaries and affiliates (the “Company”), nor its employees or representatives, make any representation or warranty (express or implied) relating to this information. By reviewing this presentation, you agree that the Company will not have any liability related to this information or any omissions or misstatements contained herein. You are encouraged to perform your own independent evaluation and analysis. Service center names, circuits, sections, and fuse IDs have been changed to protect sensitive information.

Source of Data Outage Report Event ID Date & Time Number of customers Duration of outage Type of issue Repairs made

Outage Management System Source of Data Outage Report Event ID Number of customers Duration of outage Type of issue Repairs made Date & Time Outage Management System OMS

Data Retrieval Process Outage Management System Geographic Information Service Used to ensure events occurred on the appropriate circuit. GIS OMS Database Mainframe/Server Report Generator Software Published Report Filtered Report

Circuit Section Performance Report Provides performance measures for each circuit section. SAIDI Value (with respect to the circuit) Total customer outage minutes Outage minutes for each rollup cause

Circuit Section Performance Report Circuit Information Circuit Performance Rollup Causes

Crews can choose from 81 outage causes. Rollup Causes Crews can choose from 81 outage causes. Circuit Section Performance Report condenses it to 12 rollup causes. Weather Hurricane Ice Lightning Rising water Strong wind Tornado Trees/Wind Falling dead tree Falling tree in easement Falling tree out easement Tree Tree clearance Vines

Fuse Performance Report Provides performance measures for all fuses. Total customer outage minutes Outage minutes for each rollup cause Supplements our Hot Fuse system.

Fuse Performance Report Used to identify fuses that continually have interruptions so corrective action can be taken. A problematic fuse may not be caught if it does not meet our criteria. For Example our “Three in Ninety” rule Supplements our Hot Fuse Program.

Fuse Performance Report Circuit Information Fuse Performance Rollup Causes

Identify Worst Performing Sections   Customer Minutes per Circuit Section Section SAIDI per Circuit Section Crew Miscellaneous OH equip Trees / wind Varmint SA CKT SECTION # CUSTS Ckt Priority 2015 2016 RC 5 40 407 5) New 10% 51,991 892,360 143 2,193 5,408 17,236 6,844 2,760 884,526 193 396 990 2 56 1828 89,437 716,649 49 392 2,120 2,044 1,016 4,602 106 694,047 275 304 15,652 44 6 61 129,172 574,120 116 9,412 1,422 311 4,358 89 172 125,085 566,673 1,495 3 84 250 7,797 529,908 31 801 7,750 3,468 520,066 2,092 13 307 1,109,457 513,428 3,650 1,672 508,557 572 301 187 455,240 518 43 674 211,529 503,901 313 748 1,378 295,618 11,849 18,453 72,044 172,717 1,927 3,826 1,190 1,000 9 83 48 8,683 482,238 181 10,047 8,461 222 51 520 535,661 443,216 1,034 852 7,717 803 284,497 151,173 9,992 11,791 115,377 254,093 17,867 4,417 10 646 250,757 413,563 388 640 2,262 19,651 47 221 7,210 5,903 15,921 2,200 74 153 25 78 121 952,221 382,387 476,111 3,160 219,549 252,180 732,672 Customer Count = 407 Total customer minutes = 892,360 Rollup Causes = OH Equipment Analysis: Single event. Bad pole top switch

Identify Worst Performing Sections   Customer Minutes per Circuit Section Section SAIDI per Circuit Section Crew Miscellaneous OH equip Trees / wind Varmint SA CKT SECTION # CUSTS Ckt Priority 2015 2016 RC 5 40 407 5) New 10% 51,991 892,360 143 2,193 5,408 17,236 6,844 2,760 884,526 193 396 990 2 56 1828 89,437 716,649 49 392 2,120 2,044 1,016 4,602 106 694,047 275 304 15,652 44 6 61 129,172 574,120 116 9,412 1,422 311 4,358 89 172 125,085 566,673 1,495 3 84 250 7,797 529,908 31 801 7,750 3,468 520,066 2,092 13 307 1,109,457 513,428 3,650 1,672 508,557 572 301 187 455,240 518 43 674 211,529 503,901 313 748 1,378 295,618 11,849 18,453 72,044 172,717 1,927 3,826 1,190 1,000 9 83 48 8,683 482,238 181 10,047 8,461 222 51 520 535,661 443,216 1,034 852 7,717 803 284,497 151,173 9,992 11,791 115,377 254,093 17,867 4,417 10 646 250,757 413,563 388 640 2,262 19,651 47 221 7,210 5,903 15,921 2,200 74 153 25 78 121 952,221 382,387 476,111 3,160 219,549 252,180 732,672 Customer Count = 61 Total customer minutes = 574,120 Rollup Causes = Trees/wind Analysis: Multiple events regarding slack span and tree clearance issues. Similar issues in 2015. Solution: Re-sag conductors, install cable separators.

Improve Reliability Programs   Customer Minutes per Circuit Section Section SAIDI per Circuit Section Crew Miscellaneous OH equip Trees / wind Varmint SA CKT SECTION # CUSTS Ckt Priority 2015 2016 SR 1 10001 337 13,949 62,322 129 572 600 238 658 981 9,084 35,120 10002 309 21,421 25,667 85 102 908 378 511 21,107 14,251 576 10003 59 11,835 43,020 40 146 1,519 792 2,137 5,684 907 416 7,621 18,623 235 10004 11,722 37,853 37 120 957 9,806 26,885 1,695 385 6,789 336 10005 661 127,767 4,072 558 18 2,082 184 515 1,554 90 1,230 10006 47 19,244 20,248 101 110 140 1,945 12,821 4,904 332 2,084 2,374 2 10007 1828 7,732 26,851 45 158 455 4,761 6,907 16 1,795 5,336 1,160 987 10008 121 3,610 116 64 3,030 327 160 93 10009 48 2,459 4,155 31 52 1,672 254 630 2,790 10010 250 18,769 7,516 218 87 2,366 188 7,615 2,661 130 528 4,417 278 99 Same Circuit Sections near each other Same rollup cause for majority of minutes Analysis: Circuit is not due for tree trimming, area is known to have plants/trees with a fast growth rate. Solution: Trim plants/trees. Re-evaluate trimming cycle for this area.

Fuse Report Analysis Customer Count = 392   Cust Min (excluding Crew) Cust Min (including Crew) Miscellaneous OH equip Weather Serv Area Circuit FuseID Direct & Child Fuse Custs Section 2015 2016 RC 16 77 392 60 302,232 54,096 67,816 148,176 1 25 332 20 100,601 215,168 109,913 56,870 43,731 2 24 1249 90 197,342 63,699 3 38 134 88 162,875 140,000 22,875 12 39,260 162,314 13,776 148,538 6 226 47 5,064 154,132 4,830 7 197 67 14,692 141,290 5,580 9,112 22,885 5 78 91 18 121,121 11 61 724 56 121,075 29 192 37 120,384 Customer Count = 392 Total customer minutes = 302,232 Rollup Causes = Weather Analysis: Multiple events regarding weather & lightning. Addressed through hot fuse program. Solution: Identified blown lightning arrestors and missing ground connections.

Fuse Report Analysis Customer Count = 332   Cust Min (excluding Crew) Cust Min (including Crew) Miscellaneous OH equip Weather Serv Area Circuit FuseID Direct & Child Fuse Custs Section 2015 2016 RC 16 77 392 60 302,232 54,096 67,816 148,176 1 25 332 20 100,601 215,168 109,913 56,870 43,731 2 24 1249 90 197,342 63,699 3 38 134 88 162,875 140,000 22,875 12 39,260 162,314 13,776 148,538 6 226 47 5,064 154,132 4,830 7 197 67 14,692 141,290 5,580 9,112 22,885 5 78 91 18 121,121 11 61 724 56 121,075 29 192 37 120,384 Customer Count = 332 Total customer minutes = 215,163 Rollup Causes = Weather & Miscellaneous Analysis: Not a high impact fuse. Not identified in hot fuse program. Several events related to lightning and unknown causes. Rural location. Solution: inspect and repair any damaged equipment. Replace fuse with electronic cutout sectionalizer.

Summary Our main objective is to provide recommendations, based on hard data, on where to spend CenterPoint Energy’s capital for the greatest reliability improvement.

Improvements - New Database New Software

Improvements - Tableau Data visualization software.

System Level

Service Area Level

Circuit Level

Questions