Largest utility companies in the US: ranked by revenue and by customers

This list is for anyone who sells to utilities (grid equipment, vegetation management, field services, software, engineering, customer service and staffing) and for anyone who wants to know who the biggest power companies are. It ranks utility holding companies and power producers by total operating revenue in their latest 10-K, then ranks the operating utilities that serve customers by EIA's 2025 customer counts. For oil and gas producers, see the largest oil and gas companies.

The 30 largest utility and power companies by revenue

Revenue is total operating revenue as reported in each company's 10-K for 2025 (calendar year, except TVA). Headquarters are each company's business address on its SEC filings. Employees are from the same filing; PSEG's and Ameren's 10-Ks present headcount in a form we didn't reduce to one number.

Alliant Energy ($4.36 billion) is next. Berkshire Hathaway Energy and TVA have no listed common shares but file 10-Ks; TVA describes itself as a corporate agency of the United States. NRG, Constellation and Vistra mainly generate and sell power in competitive markets. They're included because they sell electricity at utility scale, but they don't run regulated distribution networks like the others.

The largest utilities by customers

The operating utility, not the holding company, is the business that serves customers, holds the franchise and files rate cases. EIA's Form EIA-861 counts every utility's retail electricity customers each year:

EIA-861 final 2025 data, released October 7, 2026: retail customers with bundled or delivery-only service, summed across states. Texas wires companies (Oncor, CenterPoint) are counted from EIA's delivery-companies file, because in Texas's competitive market retail providers report the sales.

The largest public power utility is the Los Angeles Department of Water and Power, with 1,516,453 customers. In Texas, retail electricity providers sell to customers on the wires utilities' networks; the largest, TXU Energy and Reliant, reported 1,867,539 and 1,646,366 customers.

Who serves US electricity customers

Our sums from EIA-861 2025, bundled and delivery customers. Retail power marketers' customers are excluded so customers in competitive markets aren't counted twice. About 3.3 million more customers of small utilities that file EIA's short form appear only as state adjustments.

The sector is concentrated in employment too. The Census Bureau's Statistics of US Businesses for 2022 counts 6,772 utility firms; 35 of them have 10,000 or more employees, and together they employ 304,811 of the sector's 645,214 people (47.2%).

How these lists are built

• Revenue is total operating revenue from each company's 10-K. Holding companies consolidate all their subsidiaries, including gas utilities, pipelines and, for Berkshire Hathaway Energy, a real estate brokerage.
• Customers are EIA-861 retail customer accounts (meters billed), not people. A customer can be a house, a factory or a streetlight account.
• Left out: foreign-owned utility groups that don't file a 10-K for their US business, and gas-only utilities below the revenue cutoff. Fortune and S&P Global publish other rankings; we didn't use them.

Where the buying happens at a utility

General guidance, informed by the filings and EIA data.

• The operating utility, not the parent, usually holds the budget for distribution and customer work: vegetation management, pole and line work, metering, outage management and customer service. That's why the customer table matters for sellers.
• Rate cases shape spending. Regulated utilities recover approved spending through rates set by state commissions, so their large programs (grid hardening, meters, wildfire mitigation) are public in rate filings before contracts are awarded.
• Generation companies buy differently. NRG, Constellation and Vistra buy for power plants and retail operations, without state rate approval, and their decisions follow market prices.
• Public power and co-ops buy through boards and bids. Municipal utilities and co-ops often publish requests for proposals and buy through joint action agencies or generation and transmission co-ops.

Worked example: a grid analytics vendor targets mid-size utilities

Illustrative example. The vendor and its pricing are fictional; customer counts come from EIA-861 2025.

The seller: Feeder (feeder.example) sells outage-prediction software to electric distribution utilities at an illustrative $0.40 per customer per year.

The list. The largest utilities run long procurements, so Feeder targets the next tier: twelve investor-owned operating utilities with 1.4 million to 1.9 million customers each, including Consumers Energy (1,901,950), Duke Energy Progress (1,782,155), PECO (1,708,048), Public Service Co. of Colorado (1,605,246), Alabama Power (1,557,733), San Diego Gas & Electric (1,540,213) and Arizona Public Service (1,433,294).

The arithmetic. The twelve serve 19,377,624 customers. At $0.40 each, that's about $7.8 million a year if all twelve bought (19,377,624 × $0.40 = $7,751,050). One utility of 1.6 million customers is about $640,000 a year.

The plan.

1. Read each utility's latest rate case or grid plan for reliability programs that need outage prediction.
2. Find the distribution operations and reliability leaders at the operating utility, plus the IT owner of the outage management system.
3. Check the parent. Several of these utilities share a parent (Duke Energy, Xcel, Southern Company), so one win can lead to sister utilities.

Finding the reliability and distribution leaders and what each utility has filed with its commission is the slow part. Bebop researches each account in a list like this and drafts the first message.

Next step: for public power, co-ops and local government utilities, use the list of local governments to find the city and district owners.