Duke Energy, headquartered in Charlotte, North Carolina, is an electric power holding company in the United States, with assets also in Canada and Latin America.

Based in Charlotte, North Carolina, Duke Energy owns 58,200 megawatts of base-load and peak generation in the United States, which it distributes to its 7.2 million customers. Duke Energy's service territory covers 104,000 square miles (270,000 km) with 250,200 miles (402,700 km) of distribution lines. In addition, Duke Energy has more than 4,300 megawatts of electric generation in Latin America. It operates eight hydroelectric power plants in Brazil with an installed capacity of 2,307 megawatts. Almost all of Duke Energy's Midwest generation comes from coal, natural gas, or oil, while half of its Carolinas generation comes from its nuclear power plants. During 2006, Duke Energy generated 148,798,332 megawatt-hours of electrical energy.

Duke Energy Renewable Services (DERS), a subsidiary of Duke Energy, specializes in the development, ownership, and operation of various generation facilities throughout the United States. This segment of the company operates 1,700 megawatts of generation. 240 megawatts of wind generation were under construction and 1,500 additional megawatts of wind generation were in planning stages. On September 9, 2008, DERS updated its projections for future wind power capacity. By the end of 2008, it would have over 500 MW of nameplate capacity of wind power online, and an additional 5,000 MW in development.

The company began in 1900 as the Catawba Power Company when Dr. Walker Gill Wylie and his brother financed the building of a hydroelectric power station at India Hook Shoals along the Catawba River near India Hook, South Carolina. In need of additional funding to further his ambitious plan for construction of a series of hydroelectric power plants, Wylie convinced James Buchanan Duke to invest in the Southern Power Company, founded in 1905.

In 1917 the Wateree Power Company was formed as a holding company for several utilities that had been founded and/or owned by Duke, his family, or his associates, and in 1924 the name was changed to Duke Power. In 1927, most of the subsidiary companies, including Southern Power Company, Catawba Power Company, Great Falls Power Company, and Western Carolina Power Company were merged into Duke Power, although Southern Public Utilities, 100% owned by Duke Power, maintained a legally separate existence for the retail marketing of Duke-generated power to residential and commercial customers.

A 1973 labor dispute between mine workers and Duke Energy was the subject of the documentary Harlan County, USA. The film documents the use of "gun thugs" to intimidate striking workers.

In 1988, Nantahala Power & Light Co., which served southwestern North Carolina, was purchased by Duke and is now operated under the Duke Power Nantahala Area brand. Duke Power merged with PanEnergy, a natural gas company, in 1997 to form Duke Energy. The Duke Power name continued as the electric utility business of Duke Energy until the Cinergy merger.

With the purchase of Cinergy Corporation announced in 2005 and completed on April 3, 2006, Duke Energy Corporation's customer base grew to include the Midwestern United States as well. The company operates nuclear power plants, coal-fired plants, conventional hydroelectric plants, natural-gas turbines to handle peak demand, and pumped hydro storage. During 2006, Duke Energy also acquired Chatham, Ontario-based Union Gas, which is regulated under the Ontario Energy Board Act (1998).

On January 3, 2007, Duke Energy spun off its gas business to form Spectra Energy. Duke Energy shareholders received 1 share of Spectra Energy for each 2 shares of Duke Energy. After the spin-off, Duke Energy now receives the majority of its revenue from its electric operations in portions of North Carolina, South Carolina, Kentucky, Ohio, and Indiana. The spinoff to Spectra also included Union Gas, which Duke Energy acquired the previous year.

In 2011, Duke Energy worked with Charlotte’s business leader community to help build Charlotte into a smart city. The group called the initiative “Envision Charlotte.” At the time, the group decided on a goal to reduce energy use in the “urban core of the city by 20 percent.” To do so, the group focused on making energy consumption changes to commercial buildings larger than 10,000 square feet.

On July 3, 2012, Duke Energy merged with Progress Energy Inc with the Duke Energy name being retained along with the Charlotte, North Carolina headquarters.

Duke announced on June 18, 2013 that CEO Jim Rogers was retiring and Lynn Good would become the new CEO. Rogers has been CEO and Chairman since 2006, while Good was Chief Financial Officer of Duke since 2009, having joined Duke in the 2006 Cinergy merger. Rogers' retirement was part of an agreement to end an investigation into Duke's Progress Energy acquisition in 2012.

The company expects to spend $13 billion upgrading the North Carolina grid from 2017.

On March 16, 2006, Duke Power announced that a Cherokee County, South Carolina site had been selected for a potential new nuclear power plant. The site is jointly owned by Duke Power and Southern Company. Duke plans to develop the site for two Westinghouse Electric Company AP1000 (advanced passive) pressurized water reactors. Each reactor is capable of producing approximately 1,117 megawatts. (See Nuclear Power 2010 Program.)

On December 14, 2007, Duke Power submitted a Combined Construction and Operating License to the Nuclear Regulatory Commission, with an announcement that it will spend $160 million in 2008 on the plant with a total cost of $5 billion to $6 billion. The plant was approved in 2016.

This site will be adjacent to the old site, which was never completed and abandoned in the early 1980s, and used by James Cameron as a film set for the 1989 movie The Abyss.

In 1999 the United States Environmental Protection Agency commenced an enforcement action against Duke Energy for making modifications to very old and deteriorating coal-burning power plants without getting permits under the Clean Air Act. Duke asserted that a "modification" under the Clean Air Act did not require a permit. Environmental groups asserted that Duke was using loopholes in the law to increase emissions. Initially, Duke prevailed at the trial court level, but in 2006 the case was argued before the Supreme Court (Environmental Defense v. Duke Energy Corp. (05-848)). The Court unanimously ruled on April 2, 2007 that the modifications allowed the power plants to operate for more hours, increasing emissions, so Clean Air Act permits were needed.

In 2002, researchers at the University of Massachusetts Amherst identified Duke Energy as the 46th-largest corporate producer of air pollution in the United States, with roughly 36 million pounds of toxic chemicals released annually into the air. Major pollutants included sulfuric and hydrochloric acid, chromium compounds, and hydrogen fluoride. The Political Economy Research Institute ranks Duke Energy 13th among corporations emitting airborne pollutants in the United States. The ranking is based on the quantity (80 million pounds in 2005) and toxicity of the emissions. This change reflects the purchase of fossil fuel-heavy Cinergy, which occurred in 2005.

In early 2008, Duke Energy announced a plan to build the new, 800-megawatt Cliffside Unit 6 coal plant 55 miles (89 km) west of Charlotte, North Carolina. The plan has been strongly opposed by environmental groups such as Rising Tide North America, Rainforest Action Network, the community-based Canary Coalition as well as the Southern Environmental Law Center, which has threatened to sue Duke if it does not halt construction plans. On April 1, activists locked themselves to machinery at the Cliffside construction area as part of Fossil Fools Day.

Duke Energy has been "one of the most vocal advocates" for a "cap-and-trade" system to combat global CO₂ emissions, "and the company's CEO, Jim Rogers, thinks the company will profit from cap-and-trade". The company left the National Association of Manufacturers in part over differences on climate policy.

In a joint venture with the French-based global energy firm AREVA, under the nominal name of ADAGE, Duke Energy has planned a "Green" biomass burning facility in Mason County, Washington and is negotiating with forestland owners to secure the 600,000 tons of wood debris it needs yearly to fuel its $250 million biomass plant. The joint venture between electric power company Duke Energy and global nuclear services giant AREVA was created to build wood waste-to-energy power plants around the country.

ADAGE president Reed Wills announced the first Northwest outpost will be in the struggling timber town of Shelton, Washington.

The following pollutants are provided by DUKE-AREVA-ADAGE in their application for permit to the Department of Environmental Protection for a similar type of plant in Florida.

Following is a list of Duke Energy's thirty conventional hydroelectric facilities, in order of average electric production. All properties are 100% owned by Duke, and all but Markland are located in North Carolina and South Carolina (Markland is located in southern Indiana).

Citing the falling cost of building solar farms, Duke Energy announced plans in 2017 to launch three new such projects in Kentucky. Two will be in Kenton County and one will be in Grant County. Together the three plants will create more than 6.7 MW of power. These join several other solar farms including:

Duke Energy has been chosen as one of The 50 Best Employers In America by Business Insider

In 2002, Duke Energy was awarded the Ig Nobel Prize in Economics for "adapting the mathematical concept of imaginary numbers for use in the business world".

On February 18, 2015, Duke Energy said that it expects to settle a federal criminal probe into a 2014 North Carolina coal ash spill for $100 million.

Following a February 2, 2014 coal ash spill which was the third-largest of its kind in US history, the US Attorney's Office opened a grand jury investigation into Duke Energy and North Carolina regulators in the administration of Governor Pat McCrory. McCrory had been an employee of Duke Energy for 28 years and critics have said his administration intervened on Duke's behalf to settle lawsuits over environmental violations. The US Attorney subpoenaed over 20 officials of the McCrory administration and sought records of "investments, cash or other items of value" from Duke to regulators.

On February 14, 2011, Greenpeace launched a campaign in which Phil Radford called on Duke Energy to "not renew a single new contract for mountaintop removal coal, deliver at least a third of Duke's energy from renewable sources by 2020, and quit coal altogether by 2030." In May 2013, university student activists launched a divestment campaign against Duke Energy and other coal plant operators.

In July 2012, Duke Energy was criticized for paying former Progress Energy CEO Bill Johnson $44 million in compensation, including $10 million severance, for essentially 20 minutes on the job as Duke CEO. On July 10, new CEO Jim Rogers spoke before the N.C. Utilities Commission, explaining the reason for Johnson's dismissal as "loss of confidence". He also mentioned an "autocratic style", though some former Progress directors disagreed.

In December 2011, the non-partisan organization Public Campaign criticized Duke Energy for spending $17.47 million on lobbying and not paying any taxes during 2008 through 2010 and receiving $216 million in tax rebates, despite making a profit of $5.4 billion and increasing executive pay by 145% to $17.2 million in 2010 for its top 5 executives. The company became the object of protest for its close relationship to the Democratic Party and its funding for the 2012 Democratic National Convention.

In September 2016, the $800 billion Government Pension Fund of Norway excluded Duke and 3 of its subsidiaries, citing "Risk of severe environmental damage".

Duke Energy owns the Crystal River Energy Complex in rural Citrus County, Florida which includes the now-closed Crystal River 3 Nuclear Power Plant and four fossil-fuel power stations using coal. In late 2012, Duke paid $19 million of their 2012 property tax bill of $36 million, and filed suit against the county, claiming the assessment was too high. Duke Power owns 4,700 acres (1,900 hectares) of land and improvements assessed at over $2 billion, constituting more than a quarter of the county tax base. Citrus County Property Appraiser Geoff Greene commented, "Given the complexity, history and dispute over the last year's assessment of Duke Energy's property, an independent appraisal team was needed and tasked to arrive at a fair and just value." With the financial assistance from the Board of County Commissioners and the School Board, Greene hired two independent appraisal firms at a cost of $330,000. After five months of inspection, documentation and crunching numbers, the outside appraisal concluded that the county assessment was incorrect at $2.32 billion; it should have been $3.47 billion. Based on that figure, Duke owed the remaining $17 million for 2012 and 2013 taxes should be $54.6 million. Greene stated, "There were a lot of unreported and underreported items."