ENERGY group Scottish Power has reported losing about 200,000 customer accounts last year, as it faced tougher competition.

The company’s 2017 results revealed customer numbers fell from 5.3 million to 5.1m.

The decrease contributed to a 51 per cent drop in earnings from its retail supply division, to £98m.

Electricity generation earnings fell by 36 per cent, to £23m, following the closure of coal-burning plants, including Longannet in Fife.

However, earnings at its UK renewables division were up 44 per cent, to £316m, as it plugged in new wind farms and output increased 32 per cent.

Gas supply was down due to warmer weather last year.

Keith Anderson, Scottish Power’s chief corporate officer, said: “Completing our £650m investment in UK onshore wind in 2017 led to a good performance from the renewables business, delivering a significant increase in green electricity production.

“We now have more than two gigawatts of wind power capacity, and the £2.5 billion East Anglia ONE offshore windfarm is well in to construction. [More than] £600m was also invested in to our Networks business last year, as we continue to deliver smart and efficient grids capable of supporting the UK’s future energy needs.

“As anticipated, generation and supply continued to face challenges, predominantly in light of increasing input costs, reduced demand, challenging market conditions and political uncertainty.”

The company’s Spanish owner, Iberdrola, said yesterday it would invest €32bn over the next four years, mostly in networks, renewable energy and power purchase contracts in Mexico.

The firm, which supplies energy to more than 30m people in countries including the UK, Spain and the US, hopes to book a net profit of between €3.5 billion and €3.7bn euros in 2022, it said in a statement.

Revenue in Iberdrola’s networks business in the UK fell 7.4 per cent on lower demands and margins.

Ignacio Galan, Iberdrola and ScottishPower chairman, said: “Despite recent political and regulatory uncertainty, the UK remains a core investment destination for our company. ScottishPower will deliver around €6.1bn of investment in green and smart infrastructure over the next five years. We will focus on increasing our renewable energy capacity, enhanced grid networks and smart technology for customers.

“The UK, like the rest of the world, is at a tipping point. After 25 years of encouraging people to use less electricity, now we know that the best way to tackle climate change is to use more over the next 25 years. But as we close our final coal power stations and build more renewables this electricity will be cleaner and more affordable than ever. More and smarter power will enable us to decarbonise faster as we electrify the economy where it matters most now – in transport and in heating.

The Iberdrola forecasts were made as part of a four-year strategy update released the same time as annual earnings, which showed core profit decrease by 7.8 per cent, hurt by a drought in Spain and the depreciation of sterling against the Euro.

Hydroelectric production in Spain has plunged because of low rainfall last year.

Earnings before interest, taxes, depreciation and amortisation fell to €7.32bn at the Basque Country-based company.