Duke Energy generates revenue through regulated cost-of-service tariffs approved by state public utility commissions, with 91.5% of operating revenues coming from regulated electric sales ($27.8 billion) and 7.4% from regulated natural gas sales ($2.3 billion). The Electric Utilities and Infrastructure segment serves 8.4 million customers across six regulated utilities: Duke Energy Carolinas (3.4 million customers in North and South Carolina, 34,520 MW capacity), Duke Energy Progress (1.7 million customers in North Carolina and South Carolina, 12,559 MW), Duke Energy Florida (1.9 million customers, 6,782 MW), Duke Energy Indiana (840,000 customers, 1,173 MW), Duke Energy Ohio (740,000 electric customers plus Kentucky), and Duke Energy Kentucky. Revenue is generated through base rates (covering capital costs, depreciation, and return on equity), fuel riders (pass-through of fuel and purchased power costs with no markup), and grid modernization riders (recovering transmission, distribution, and smart grid investments). In FY2024, fuel and purchased power costs were $9.2 billion (30.3% of revenue), operation and maintenance expenses were $5.4 billion (17.8%), depreciation was $5.8 billion (19.1%), property taxes were $1.5 billion (4.8%), and interest expense was $3.4 billion (11.1%). The cost structure is dominated by fixed costs: depreciation, interest, and property taxes together account for 35% of revenue, meaning the company must grow its rate base continuously to cover these costs while earning its allowed return. The regulatory model works as follows: Duke Energy files a rate case with state commissions, requesting a revenue requirement based on projected costs, an approved equity ratio (typically 50-53%), and an allowed return on equity (typically 9.5-10.5%). The commission reviews the filing, holds hearings, and issues an order that may grant the full request, a partial request, or deny the request. In 2024, Duke Energy secured rate increases in South Carolina ($234 million annual increase, 9.94% ROE, 51.21% equity ratio), Indiana ($295.7 million, 9.75% ROE), and North Carolina Year 2 of multiyear plan ($126 million). These increases added approximately $600 million in annual revenue. The Gas Utilities and Infrastructure segment operates through Piedmont Natural Gas (serving 1.1 million customers in North Carolina, South Carolina, and Tennessee), Duke Energy Ohio gas distribution, and midstream pipeline investments including the Sabal Trail and Cardinal pipelines. Gas utility revenue is generated through base rates and gas cost recovery mechanisms, with operating income of $798 million in FY2024 and segment income of $454 million. The segment faces regulatory pressure to reduce methane emissions, with Duke Energy committing to net-zero methane emissions from its gas business by 2030. The business model's vulnerability is regulatory lag: the time between when costs are incurred and when they are recovered through rates. Duke Energy's $15.0 billion in annual capex creates a financing gap that must be bridged by debt issuance ($11.4 billion in FY2024) and equity issuance, diluting returns if rate cases are delayed or reduced. The company also faces weather risk: mild winters reduce heating load and cool summers reduce air conditioning load, directly impacting revenue. In FY2024, favorable weather contributed approximately $0.10 per share to earnings compared to normal weather. Storm costs, which totaled $1.2 billion in FY2024 (including Hurricanes Helene and Milton), are recovered through storm riders and securitization, but the recovery process takes 12-24 months and creates cash flow timing mismatches.