NextEra Energy (NYSE:NEE) is the most valuable utility company in the world, far ahead of Iberdrola (OTC:IBDSF) and Southern Company (NYSE:SO). Electrical utility companies dominate the top of the market, and there's a mix of U.S. and international companies represented.
Largest utilities
Largest companies by market cap in the utilities sector
(Editor's note: Rankings are as of Sept. 4, 2025.)
| Name and ticker | Market cap | Current price | Industry |
|---|---|---|---|
| NextEra Energy (NYSE:NEE) | $175 billion | $84.48 | Electric Utilities |
| Iberdrola (OTC:IBDSF) | $128 billion | $19.82 | Electric Utilities |
| Southern Company (NYSE:SO) | $108 billion | $97.84 | Electric Utilities |
| Constellation Energy (NASDAQ:CEG) | $124 billion | $386.71 | Electric Utilities |
| Duke Energy (NYSE:DUK) | $99 billion | $128.54 | Electric Utilities |
| Enel SpA (OTC:ENLAY) | $100 billion | $9.94 | Electric Utilities |
| National Grid Plc (NYSE:NGG) | $75 billion | $76.97 | Multi-Utilities |
| Vistra (NYSE:VST) | $71 billion | $201.55 | Independent Power and Renewable Electricity Producers |
| American Electric Power (NASDAQ:AEP) | $63 billion | $117.57 | Electric Utilities |
Companies 1-3
1. NextEra Energy
- Market cap: $147.51 billion (as of Sept. 4)
- Revenue (TTM): $25.9 billion
- Gross profit (TTM): $16.1 billion
- Five-year annualized return: 3.00%
- Year founded: 1925 (Florida Power & Light), 1984 (FPL Group)
TTM = trailing 12 months.
NextEra Energy is a leading utility and renewable energy company. It has multiple subsidiaries, the largest of which is Florida Power & Light, the largest electrical utility company in the U.S.
It supplies power to approximately 12 million people across Florida. Another subsidiary, NextEra Energy Resources, is one of the country's largest generators of renewable energy, including wind energy and solar energy.
2. Iberdrola
- Market cap: $119.08 billion (as of Sept. 4)
- Revenue (TTM): $52.2 billion*
- Gross profit (TTM): $28.1 billion*
- Five-year annualized return: 12.33%
- Year founded: 1907 (Hidroelectrica Espanola), 1944 (Iberduero), 1992 (merger of Hidroelectrica Espanola and Iberduero)
*Converted from euros.
Iberdrola is a Spanish electrical utility company with subsidiaries throughout the world, including in the U.S., the U.K., and Brazil. It serves more than 36 million customers worldwide and is the leading European electrical utilities company by market cap.
This company first committed to using renewable energy in 2001. In 2024, it set an all-time high with 83,300 gigawatt-hours (GWh) of clean energy production. In July 2025, it sold its Mexican power businesses for $4.2 billion in an effort to focus more on its U.S. and U.K. networks.
3. Southern Company
- Market cap: $100.83 billion (as of Sept. 4)
- Revenue (TTM): $28.4 billion
- Gross profit (TTM): $13.8 billion
- Five-year annualized return: 16.24%
- Year founded: 1945
Southern Company is a gas and electric company that serves 9 million customers across the southern U.S. Along with its subsidiaries, it owns or operates 55 facilities in 15 states.
Utilities companies often pay out generous dividends, and Southern Company is no exception. It has a high dividend yield and has raised its dividend for more than 20 consecutive years.
Companies 4-6
4. Constellation Energy
- Market cap: $96.37 billion (as of Sept. 4)
- Revenue (TTM): $24.8 billion
- Gross profit (TTM): $5.4 billion
- Year founded: 2022
Constellation Energy is an electricity and natural gas company with solar, wind, nuclear, and hydropower generation facilities. Based in Baltimore, Maryland, it serves residential, business, and public sector customers.
Constellation Energy has had an exciting 2025. In January, it announced an agreement to purchase Calpine Corp., a natural gas and geothermal power producer. The company said the acquisition makes Constellation Energy the country's largest clean energy provider.
In June, Meta Platforms (NASDAQ:META) signed a 20-year nuclear power agreement with Constellation Energy. Starting in 2027, Meta will buy power from a Constellation Energy Center in Illinois that was previously in danger of closing.
Meta isn't the only tech giant to partner with Constellation. Microsoft (NASDAQ:MSFT) signed its own 20-year agreement with Constellation in 2024 to buy power from the Crane Clean Energy Center in Pennsylvania, formerly known as the Three Mile Island Unit 1 nuclear plant.
5. China Yangtze Power
- Market cap: $96.72 billion* (as of Sept. 4)
- Revenue (TTM): $12.1 billion*
- Gross profit (TTM): $7.3 billion*
- Five-year annualized return: 7.13%
- Year founded: 2002
*Converted from Chinese yuan.
China Yangtze Power, headquartered in Beijing, is a largely state-owned utility company specializing in hydroelectric power generation. It owns all the power-generation assets of six hydropower stations along the Yangtze River and manages the Three Gorges Dam, the world's largest hydropower plant.
6. Duke Energy
- Market cap: $94.48 billion (as of Sept. 4)
- Revenue (TTM): $31.3 billion
- Gross profit (TTM): $16.0 billion
- Five-year annualized return: 12.70%
- Year founded: 1904
Duke Energy is an electric and natural gas company based in Charlotte, North Carolina. It generates electricity through coal, natural gas, nuclear, hydroelectric, and renewable power sources.
Duke Energy is making substantial investments in improving its electric grid and renewable energy production. It announced a five-year plan with $73 billion in capital expenditures in 2024 and decided to raise the amount to $83 billion in 2025.
Companies 7-10
7. Enel Spa
- Market cap: $92.31 billion (as of Sept. 4)
- Revenue (TTM): $86.2 billion*
- Gross profit (TTM): $42.9 billion*
- Five-year annualized return: 7.08%
- Year founded: 1962
*Converted from euros.
Enel SpA is an Italian distributor of electricity and natural gas. It operates in 43 countries, has more than 1,000 subsidiaries, and connects more than 70 million users to its grids.
This company produces electricity from a number of renewable and nonrenewable energy sources. These include solar, wind, hydroelectric, geothermal, thermal, and nuclear power.
8. National Grid
- Market cap: $68.04 billion (as of Sept. 4)
- Revenue (TTM): $24.7 billion*
- Gross profit (TTM): $19.1 billion*
- Five-year annualized return: 9.79%
- Year founded: 1990
*Converted from British pounds.
National Grid is a London-based utility that handles the transmission and distribution of electricity and gas. It primarily operates in the U.K., where it distributes electricity to 8 million customers across a 21,351-square-mile service area.
This company also has a presence in the U.S. It owns and operates electricity distribution networks, electricity transmission facilities, and gas distribution networks around the northeastern U.S.
On a negative note, National Grid's failure to maintain an electricity substation led to a March 2025 fire at London's Heathrow Airport. The airport had to be closed for almost 18 hours, leading to significant financial losses for airlines.
9. Vistra
- Market cap: $63.74 billion (as of Sept. 4)
- Revenue (TTM): $18.5 billion
- Gross profit (TTM): $7.4 billion
- Five-year annualized return: 63.54%
- Year founded: 2016
Vistra is an electricity and natural gas company headquartered in Irving, Texas, and with operations in 20 states. In May 2025, Vistra bolstered its operations when it signed an agreement to buy seven natural gas power plants from Lotus Infrastructure Partners for $1.9 billion.
The company is also the biggest polluter in the U.S., according to one study, ranking at the top of the Greenhouse 100 Polluters Index in 2024, ahead of Southern Company and Duke Energy.
10. American Electric Power Company
- Market cap: $58.84 billion (as of Sept. 4)
- Revenue (TTM): $20.7 billion
- Gross profit (TTM): $12.9 billion
- Five-year annualized return: 10.83%
- Year founded: 1906
American Electric Power Company is an electrical utility company serving approximately 5.6 million customers across 11 states. It boasts the largest electricity transmission network in the country, at 40,000 miles.
Like other major utilities companies, American Electric Power Company is prioritizing clean energy. It's investing $8.6 billion in renewable energy through 2027 and aiming to grow its renewable generation portfolio to 50% by 2030.
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Takeaways
Utilities sector takeaways for investors
Utilities companies are generally stable, conservative investments. They have reliable earnings since demand for utilities doesn't fluctuate much, regardless of economic conditions.
This predictability means that utilities companies often underperform compared to the stock market as a whole. Among the largest utilities companies, only two out of nine delivered market-beating returns over the last five years (one, Constellation Energy, hasn't been in business for five years yet).
And even though utilities companies are known for stability, they aren't immune to market volatility. The sector is facing uncertainty due to rising materials costs brought on by the Trump administration's import tariffs, assuming those tariffs remain in place. A federal court ruled that most of these tariffs are illegal, but the Trump administration is appealing the decision.
On a positive note, the consistent profitability of utilities companies means that many of them are excellent dividend stocks. Some of the companies on this list have extremely high dividend yields. Overall, the utilities sector will be a good match for investors in search of passive income or just a fairly stable investment.
