Based in Chicago, Illinois, Exelon is a Fortune 100 company and one of the largest electricity organisations in America. 

The company is a stalwart investor in renewable energy. However, despite being located in the 'windy city', Exelon's renewable fuel of choice is nuclear. With full or partial ownership of 23 reactors, the company owns a total capacity of 35,000MW. 

Southern Company is an electric and gas utility company which lives up to its name. Proudly located in Atlanta, Georgia, Southern also has executive offices in Birmingham, Alabama.

Serving six states - Alabama, Georgia, Illinois, Mississippi, Tennessee and Virginia - the company has 9mn customers and is listed on the Fortune 500. 

Spanish multinational Iberdrola has achieved a widespread customer base of over 31mn people across four continents. 

Holding many subsidiaries, including Scottish Power and Avangrid, the company is ranked as the top wind energy producer in the world and one of the largest generally. It had a revenue of €36bn in 2019.

Supplying energy to several states in east of America, including Illinois, North Carolina and West Virginia, Dominion Energy has a total asset portfolio of 27,000MW.

Generating the majority of its power through natural gas (32%) and nuclear fission (22%), the company strives to provide cleaner energy to its customers. For 2019, Dominion posted revenues of $16.5bn.

Based in Rome, Italy, Enel is a multinational active in the generation and distribution of electricity, as well as having interests in natural gas.

The company has revenues of $89bn in 2019 and is actively pursuing renewable energy projects. It recently announced its 2020-2022 plan aiming to maximise value through sustainability.

Électricité de France, or EDF, is headquartered in Paris, France. Featuring a rich and diverse portfolio of investments and interests, including nuclear, hydroelectricity and fossil fuels, the company has an impressive total capacity in excess of 120GW.

The company took a revenue of €71.3bn in 2019, placing it comfortably within the top echelon of global utility companies.

A Fortune 200 company, NextEra Energy has a total capacity of 45,900MW and generated $19.2bn of revenue in 2019. 

Headquartered in Juno Beach, Florida, NextEra provides power to an estimated 10mn people - making it the third-largest electricity provider in America - and has numerous subsidies, including Florida Power & Light and Gulf Power Company.

Known as one of the largest 'investor-owned' utility companies in the world, National Grid had revenues of £15bn in 2019 and currently provides 20mn customers with gas and electricity. 

Although headquartered in London, UK, the company also has activities in Northeast America, specifically New York, Rhode Island and Massachusettes. National Grid is listed on the LSE, NYSE and the FTSE 100.

French multinational ENGIE posted revenues of €60.1bn in 2019, placing it amongst the most profitable and successful utility companies currently in operation.

Formed in 2008 when Gaz de France and Suez merged together, ENGIE employs over 158,000 people worldwide and has recently decided to wean itself off of fossil fuels in favour if renewable energy projects and investments.

Founded in 1904 and headquartered in Charlotte, North Carolina, Duke Energy possesses a 58,200MW capacity generated from coal, gas and oil. The company currently serves over 7.2mn customers.

In addition to generating a lot of electricity, Duke, one of the largest companies in the US, posted a revenue of over US$25bn in 2019.