[4] As of 2023,[update] the largest shareholder of the company is the Qatar Investment Authority, with BlackRock and Norges Bank (managers of the Norwegian Government Pension Fund Global) also holding significant interests.

In 1840, American entrepreneurs founded the Hartford City Light Company, which lead to the incorporation of Energy East on the eastern seaboard of the US, which would much later become Iberdrola USA.

In Spain, which had experienced a period of economic growth at the start of the 20th century, the industry suffered a severe setback in 1936 whose impact would be felt for the following two decades: the Spanish Civil War abruptly halted development, destroyed facilities and made maintaining the remaining equipment extremely difficult.

Notably, the president between 1935 and 1985 of one of the former mergers, Hidroeléctrica Española, José María de Oriol y Urquijo, was a relevant Spanish nationalist who allegedly declared to have been part in the investigation and prosecution of more than 80.000 people in the Basque Country.

That same year, following the integration of Iberdrola USA and UIL Holdings Corporation, Avangrid was established and began trading on the New York Stock Exchange.

[37][38]  In the United States, the purchase operation of PNM Resources, the electricity company of New Mexico and Texas, was pending permission from the Regulatory Commission.

[41][42] In 2021, Iberdrola announced, through its British subholding ScottishPower, the investment of an additional 6 billion pounds (7,090 million euros) in the construction of the East Anglia Hub offshore wind farm (North Sea – United Kingdom).

Specifically, their collaboration includes investing €1 billion to deploy a network of 11,700 fast and ultra-fast charging points for electric vehicles in Spain and Portugal.

[61] According to the data published by the National Securities Market Commission (CNMV) in July 2023, the company has increased its renewables installed capacity by 6.5% worldwide in the last 12 months, reaching a total of 41,246 MW.

[63] The European Investment Bank and Iberdrola have signed a €1 billion financing arrangement in 2023 to develop 19 solar power plants and three onshore wind farms in Spain, Portugal, and Germany.

[64][65] In 2024, Iberdrola reaches an agreement to purchase the remaining 18.4% of its US subsidiary, Avangrid and inauguration of the group's fourth offshore wind farm, Saint Brieuc, in France.

In 2010 Iberdrola sold their ownership of GESA, majority share owner of EEGSA (Empresa Electrica de Guatemala) to Grupo EPM.

[107][108] In the U.S., Iberdrola's Midland onshore wind project in Illinois has a total capacity of 106 MW, fully installed by December 2022, with operations starting in 2023 under a Power Purchase Agreement.

Scotland is home to a notable number of Iberdrola's onshore facilities, such as Hagshaw Hill, Beinn a Tuirc, Black Law I and II, Whitelee and its extensions, and the more recent Kilgallioch and Halsary projects.

[130] As of 2023, Iberdrola's installed PV capacity exceeds 4,500 MW in USA, Mexico, Brazil, UK, Spain, Australia, Portugal, Italy and Greece.

In Great Britain, Iberdrola, through its British subsidiary ScottishPower, agreed to purchase seventeen photovoltaic solar energy projects in the United Kingdom, totalling a combined capacity of more than 800 MW.

[153] In May 2021, the company started a joint project with Cummins regarding the 500MW-per-year facility hydrogen electrolyser gigafactory in Spain, in the central region of Castilla-La Mancha, near Madrid.

For instance, in Maine, Avangrid Hydroenergy operates the Forest City Hydroelectric Facility, which has a capacity of 23.5 MW, providing power to approximately 15,000 households annually.

Additionally, in Connecticut, Avangrid Hydroenergy operates the Shepaug Hydroelectric Facility, which has a capacity of 10 MW, supplying power to thousands of households.

[168] The electric power line connecting the states of Minas Gerais and São Paulo, with a length of more than 1,700 kilometres, is Iberdrola's largest grid project worldwide.

Its shares are listed in the Brazilian stock exchange, and it comprises interests in the companies of distribution, generation, renewable energy, transmission, and electricity retail businesses operating in Brazil.

It has installed capacity of 292 MW and is located between the towns of El Almendro, Alosno, San Silvestre and Puebla de Guzmán in the south of Huelva province.

Located in Kennedy County, Texas, its innovative features include a radar that detects the arrival of large flocks of migratory birds and shuts down the turbines if visibility conditions represent a danger.

Some of its projects include: Protagonists of their Future (aimed at women victims of gender-based violence and at risk of social exclusion),[208] SUMA (aimed at the return of women to work after a break in their professional career), INVOLVE (International Volunteering Vacation for Education, within which Iberdrola employees help vulnerable teenagers to improve their employability through computer science and web applications),[209] Lights... and Action!

(a project carried out since 2011 with the Tomillo Foundation aimed at improving the training and employability of young people who study basic vocational training for teenagers with experiences of school failure), The Job Ambassadors Programme (volunteers have participated in the training of people from the Multiple Sclerosis Foundation (EMF) who are seeking employment), Environmental Volunteering (Forest Restoration on International Forest Day, with 1,100 trees planted through various initiatives in which people with intellectual and school disabilities have also participated),[210] initiatives to encourage scientific vocation and equal opportunities on International Women's and Girls’ Day in Science and on Women's Day, World Cancer Day (initiatives to raise awareness of the importance of supporting research and hair donation for vulnerable, underprivileged women),[211]  International Happiness Day (1,600 meals distributed to vulnerable families), SDGs at school (a school awareness project on SDGs) I Can (a project that prepares people with intellectual disabilities to secure and keep a job and lead an independent life).

The company also raised funds, doubling the amounts donated by its employees for the United Nations High Commissioner for Refugees (UNHCR) to provide shelter, immediate food and emergency care.

[213] Also in 2022, Iberdrola guaranteed gas and power supply for five months to customers in Spain who were deemed vulnerable by the humanitarian group the Red Cross.

Residential customers also received help in paying their bills over longer periods if the Red Cross assessed their circumstances and considers that they were vulnerable.

[214] In February 2022, Ignacio Galán, the Chairman of Iberdrola, together with businessmen from the European Round Table for Industry (ERT), the President of France Emmanuel Macron, the German Chancellor, Olaf Scholz and the President of the European Commission, Ursula Von der Leyen, held a meeting in Paris to address the Russian aggression against Ukraine and to promote ways for peace in Europe.

[215] The company promotes 32 National Federations (including the National Federations of Athletics, Badminton, Handball, Boxing, Ice Sports, Fencing, Football, Gymnastics, Hockey, Karate, Canoeing, Rugby, Surfing, Table Tennis, Triathlon and Volleyball, to which in 2018 were added Underwater Activities, Bowling, Winter Sports, Weightlifting, Judo, Olympic Wrestling, Mountaineering and Climbing, Swimming, Skating, Ball, Rowing, Squash, Taekwondo, Tennis, Archery and Sailing), and has more than 100 competitions with the naming right Iberdrola, including 32 leagues.