Scottish Power’s profits have slumped by almost 80% after the big six energy supplier lost about 165,000 customers in the past year.

The supplier, owned by the Spanish utility company Iberdrola, blamed mild winter weather and the government’s energy price cap for the sharp drop in profits.

Scottish Power reported profits of £37.4m for the first nine months of the year, down from £170m in the same period last year when freezing weather, brought by the “beast from the east” storm, increased the amount of gas and electricity used in homes.

Scottish Power said it had sold 10% less electricity and 8% less gas this year, in part because the weather had been milder but also due to a fall in customer numbers from 4.78 million this time last year to 4.62 million.

The legacy big six energy companies have lost their stranglehold on the energy market in recent years due to a surge in new cut-price energy suppliers entering the market.

Scottish Power reported far healthier profits in its renewable energy and energy networks business units, which are continuing to grow in line with the appetite for clean energy and “smart” energy grids.

SP Energy Networks, which is regulated by Ofgem, reported profits of £626m for the first nine months of the year, up by 6% from last year. At Scottish Power Renewables, which owns a stable of onshore and offshore wind farms, profits grew by 13% to £302m.

Keith Anderson, the chief executive of Scottish Power, said the company had ploughed a record £2bn of investment into its renewable energy business to start up its East Anglia One offshore windfarm off the Norfolk coast.

“As the UK’s only integrated, 100% green energy company, our ongoing investment in smarter grids, digital systems and renewable generation will be critical to the country meeting 2050 net zero targets,” he said.

Scottish Power sold off its last remaining fossil fuel power plants early last year in a £700m deal with Drax, to focus its investments on windfarms and power grids.

Iberdrola invested a total of €4.7bn (£4bn) this year, mainly in renewable energy and energy networks, and reaped profits of €2.5bn for the first nine months of the year, up by a fifth from last year.

Iberdrola’s chairman and chief executive, Ignacio Galán, said: “These achievements provide us additional room for new investments, creating a virtuous circle of growth and financial strength.”



