Renewables giant Iberdrola plans to invest €5.4bn ($6.9bn) in the UK over the next couple of years.
Two-thirds of the total investment will be in Scotland, primarily to develop wind farms, smart grids and carbon capture.
The investment will also include purchases from Basque suppliers and their Scottish counterparts.
Through ScottishPower, Iberdrola plans to play a key role in the British energy sector through its investments in wind power, nuclear energy and clean coal, the company said in a statement.
The firm intends to start up a number of offshore wind farms in the country including a 7,200MW offshore wind farm for which Iberdrola Renovables and Vattenfall have been awarded the rights.
Iberdrola also holds additional 2,300MW in the pipeline in the UK including the 500MW West of Duddon Sands wind farm being developed in partnership with Dong.
The firm also plans to gradually roll out smart electricity grids across the UK starting with installations at Glasgow.
In a joint venture with GDF Suez and Scottish and Southern Energy (SSE), Iberdrola will also participate in the programme to construct nine new nuclear power plants in the UK.