地下化与PSPS：野火弹性电网的成本权衡决策

The Cost Tradeoff Decisionfor a Wildfire-Resilient Grid Utilities face a tough tradeoff when it comes tomanaging wildfire risk: continue absorbing the highcosts of Public Safety Power Shutoffs (PSPS), orinvest in long-term solutions like undergrounding high-risk electric distribution lines. The critical economicquestion at the center of the debate — is spendingmore upfront the only practical way to avoid fargreater losses down the line? A single one-hour summer-afternoon outage costsan average large commercial or industrial customerapproximately $82,000 and an average small ormedium commercial customer approximately $1,200,according to Lawrence Berkeley National Laboratory’soutage-cost research, which serves as the basisfor the industry-standard Interruption Cost Estimate(ICE) calculator. These figures scale substantiallyfor the multi-hour shutdowns that now define PSPSoperations across the U.S. West.2 Once prohibitively expensive, distributionundergrounding is increasingly benefiting fromindustrialized delivery models, with standardizeddesigns and strategic sourcing helping drive downper-mile costs. That cost discipline, however, doesnot extend to transmission, where undergroundingremains a capital intensive option constrained byterrain, permitting, and routing realities. Set against event-driven losses, the ratepayer cost ofundergrounding the highest wildfire-risk distributioncircuits is finite, recoverable over time, and comeswith a measurable reduction in risk. In its 2023 General Rate Case decision for PG&E,the California Public Utilities Commission (CPUC)authorized undergrounding 1,230 miles of distributionlines in the highest fire-risk areas — an action thatincreased the typical residential customer’s combinedmonthly electric and natural gas bill by approximately$32.62 in 2024.3The CPUC and PG&E assessed thatthis investment would eliminate nearly 98% of wildfirerisk on the underground sections and reduce the needfor PSPS across that corridor.4 With undergrounding now central to building gridresilience, the next general rate case cycle willdetermine whether utilities can justify large-scaledeployment through circuit-level economics that weighavoided outages and wildfire risk reduction againstfiscal accountability. The Cost of GoingDark — and theEconomics of KeepingLights On That cost asymmetry — open-ended, recurringPSPS exposure on one side and a finite, recoverableinvestment on the other — is the central argument ofthis paper. Distribution undergrounding converts anescalating climate-driven liability into a fixed capitalcost with clear reliability benefits. For utilities, regulators and ratepayers, the debateis no longer whether undergrounding is justified inthe highest-risk corridors, but how quickly capitalprograms can scale to deliver it, and how clearly thattradeoff can be presented to the commissions thatmust approve it. PSPS are the industry’s most visible near-termtool for preventing utility-ignited wildfires, but theireconomic toll on ratepayers and regional economiesis substantial. The Stanford Woods Institute forthe Environment estimated that PG&E’s October2019 shutoff alone cost the California economyapproximately $2 billion, with small commercial andindustrial customers bearing a disproportionate shareof the burden.1 This shift is being supported by a rare convergenceof regulatory and federal policy. The CPUC and theFederal Energy Regulatory Commission (FERC)have tightened cost-discipline requirements whileproviding clear pathways for undergrounding projectsthat demonstrate superior long-term risk-reduction.8Furthermore, recent federal budget allocationshave directed funding toward grid deployment andtransmission reliability and resilience (TRR) to supportthese infrastructure upgrades.9 The ResilienceTipping Point:Undergrounding as aCore Grid Strategy Undergrounding has shifted from a discretionaryaesthetic enhancement to a foundational pillar ofgrid resilience. Federal frameworks and utility capitalplans have repositioned undergrounding as a frontlinedefense against intensifying climate-driven risk. The case for undergrounding is not limited to wildfirerisk mitigation, it can be aesthetic and environmentalas well. In the U.K., for instance, the Visual ImpactProvision (VIP) demonstrates how undergrounding canbe economically justified in protected landscapes.10 While approximately 20% of the U.S. electricdistribution system is now underground, transmissionundergrounding remains a specialized application.Only a tiny fraction of transmission lines at or above200kV are underground, with historical estimates aslow as about 0.5% of the total system.5 Climate Change,Droughts, and theRising Threat For utility leaders, the pilot phase is over. It is nowa period of high-conviction, data-driven execution,where underground assets must demonstrablyoutperform conventional alternatives.6 The urgency of grid hardening is amplified by thesevere drought gripping the U.S. West. The winter