Item 11- Presentation Underground Feasibility Study — original pdf

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Underground Feasibility Study A step toward a comprehensive Distribution Resiliency Plan David Tomczyszyn Vice President, Electric System Engineering & Technical Services Austin Energy Arlin Mire Project Manager, Utility Investment Planning 1898 & Co. Lisa Martin Deputy General Manager & Chief Operating Officer Austin Energy March 2025 © Austin Energy Item 11Agenda Austin Energy System Overview & Background Undergrounding Feasibility Study Next Steps & Questions David Tomczyszyn Arlin Mire Lisa Martin 2 Distribution Resiliency Plan Overhead Hardening Study Underground Feasibility Study Distribution Resiliency Plan Existing Reliability Programs 3 What Is Driving the Need for a Comprehensive Plan? Winter Storms Growth High Winds & Wildfires Record Heat 4 Reliability and Resilience Reliability • Performing consistently well • Performs intended function without failure over time and in specified conditions Resilience • Capacity to withstand or recover quickly from difficulties • Toughness • The ability to spring back into shape Distribution Reliability Performance of the distribution system as originally designed, built and operated for safety, power quality and infrastructure protection Distribution Resilience Reliability factors, plus incorporating self-healing and hardening techniques to withstand and recover more quickly from unplanned events 5 Austin Energy’s System Overview Transmission Distribution 6 Undergrounding Feasibility Study Austin Energy Utility Oversight Committee March 5, 2025 1898 & CO. - PART OF BURNS & MCDONNELL 1898 Founded 90+ Offices Worldwide 14,500 Professionals 7th #1 Largest Design Firm Power ASSET PLANNING & MANAGEMENT FINANCIAL ANALYSIS Top 5 Aerospace, Oil & Gas, Chemicals, Pipelines, Data Center Confidential Information ENTERPRISE TECHNOLOGY DATA & ANALYTICS *Industry rankings based on Engineering News-Record (ENR) 2023 Top Design Firms 8 OUR PROCESS AND EXPERIENCE Data-Driven Capital Portfolios System-Wide Undergrounding Study Experience (SPS Only) 9 UNDERGROUNDING FEASIBILITY STUDY OVERVIEW • 1898 & Co. Feasibility Study Steps 1. Broke up entire overhead system into 5,000 sections Note: A section does not necessarily equal a mile 2. Estimated costs to underground each section individually 3. Calculated lifecycle benefit of undergrounding for each section individually, including… • Reduced future costs from equipment repairs, pole inspections, vegetation management cost • Reduced future customer outages & converted to a monetary, societal value • Undergrounded Section Benefits = Reduced Future Costs + Reduced Future Customer Outages ($) 4. Compared each section’s Benefits to the Undergrounding Cost with a Benefit to Cost Ratio • Benefit to Cost Ratios of 1.0 or greater means benefits may exceed costs • 33 sections out of the 5,000 (~120 miles) have a benefit to cost ratio 1.0+ 10 FEASIBILITY STUDY: CORE DATA USED TO CALCULATE COSTS 11 FEASIBILITY STUDY: UNDERGROUNDING BENEFITS • Avoided Future Austin Energy Costs • Equipment Failures • Pole, conductor, transformer replacements • Storm / weather event restoration costs • Equipment Maintenance • Vegetation management costs • Pole inspection and maintenance costs • Avoided Future Customer Outages • Significantly Reduces/Eliminates Outages • Equipment, Vegetation, Weather, Animal • Converted to Economic Dollar Benefits • U.S. Department of Energy’s Interruption Cost Estimator (ICE) Tool • Societal benefit appropriate for benefit-to-cost calculations for project evaluation/comparison Total Lifecycle Benefits (Present Value $) Avoided Future Austin Energy Costs Avoided Future Customer Outages (Monetized) 12 FEASIBILITY STUDY: DEPTH TO ROCKY SOIL • Underground cable installed ~4 ft depth • Much of overhead system overlaps soil that is restrictive within 4 ft depth 13 FEASIBILITY STUDY: ENVIRONMENTAL IMPACT 70% of overhead lines are in sensitive areas • Environmental • Karst Zones • Critical Habitats • National Wetland Inventory • Preserves/Conservation • Historic • Archaeological Sites • Cemeteries 14 FEASIBILITY STUDY: FIELD OBSERVATIONS • Visited over 40 system sections across territory • Distributed across 10 districts and unincorporated area • Recorded observations • Asset conditions • Structure configurations • Right-of-way conditions • Observable technical / engineering challenges • Environmental challenges 15 FEASIBILITY STUDY: ADDITIONAL UNCERTAINTIES Additional information can be gathered to reduce some uncertainties, but reduction in uncertainty does not always correlate to reduction in cost • Uncertainties affect project planning, engineering, and costs and add technical challenges • May require detailed, site-specific evaluation to estimate costs, including • Telecommunication relocation costs • Handling of secondary and customer services • Contracting costs • Tight space within existing easements / acquiring additional easements • Dense vegetation areas / critical root zones • High customer density • Environmental risks 16 UNDERGROUNDING RECOMMENDATIONS 1898 & Co. does not recommend system-wide overhead to underground conversion of Austin Energy’s distribution system • Cost • $50 Billion to move all overhead to underground • Only a few system sections have benefits that exceed costs (33 out of 5,000 sections), but other project solutions may be better than undergrounding • i.e., Benefit Cost Ratio >= 1.0 does not mean ‘you should underground this section’ • Wide range of technical challenges mean specific project costs may vary greatly • Notable Challenges • Environmental impacts, space within underground easements, acquiring permits, telecom relocation, rocky soils, traffic control • Recommend Austin Energy develop a highly strategic approach to undergrounding. Include study results and data in a larger strategy for reliability and resilience 17 18 Where Do We Go From Here? Key Objective: Reliability + Resiliency Underground New Development Vegetation Mgt. & Wildfire Mitigation Strategic Underground Analysis Overhead Hardening Study Stakeholder Engagement Distribution Resiliency Plan 19 Next Steps Timeline Analyze Undergrounding Study Results Receive Overhead Study Results Ongoing May 2025 Develop Comprehensive Distribution Resiliency Plan Use studies, further analysis and stakeholder engagement to inform near- and long-term priorities Present Distribution Resiliency Plan Late 2025 20 QUESTIONS? ©Austin Energy. All rights reserved. Austin Energy and the Austin Energy logo and combinations thereof are trademarks of Austin Energy, the electric department of the City of Austin, Texas. Other names are for informational purposes only and may be trademarks of their respective owners.