The company confirmed on Friday that Iberdrola subsidiary, Scottish Power Renewables, is buying 12 solar plants that Elgin is building in the UK.
Neither side revealed the price, but Iberdrola noted in its statement that the plants will need a total investment of more than £300 million sterling (€360 million).
Once built and operating, they will be capable of generating enough electricity to power more than 144,000 homes.
The deal also includes batteries used to ensure steady electricity supplies from renewable generators.
Ronan Kilduff, Elgin’s chief executive, welcomed the news. He said that the Irish company would continue working on its Irish, British and Australian projects.
Iberdrola said that the deal would bring to almost 30 the total number of projects that it has bought over the last two years.
The Spanish group plans to spend €150 billion over the next decade on tripling its capacity to generate green electricity.