Energy group Drax today hailed record sales at its Ipswich-based retail arm Haven Power, a specialist supplier of electricity to busineses.

Drax, which also has coal and biomass generation businesses, reported underlying earnings of £46million for 2015, down from £96m in the previous 12 months.

It said earnings were in line with expectations, despite “severe market deterioration and difficult regulatory challenges”, but warned of a “challenging” outlook for 2016 amid a continuing fall in prices and the loss of climate change levy exemption certificates for renewables.

However, Haven Power achieved record sales of 13.8TWh (terrawat hours) of electricity, compared with 11.8TWh the previous year.

“Our customer proposition remains compelling as does our ability to deliver a service that consistently exceeds expectations,” it said. “This means that we have one of the best renewal rates in the industry.

“Over the period we were delighted to welcome Thames Water as a new customer (further demonstrating our strength in the utilities market), as well as many others.”

Although the removal of the climate change levy exemption had had “a signifcant negative impact” on the business, Haven had become the first in the market to respond with a new product, Biomass Renewable Electricity, it added.

Dorothy Thompson, chief executive at Drax, said: “In a challenging year we have delivered another strong operational performance and realised our vision to become a predominantly biomass fuelled generator.”

She added: “The fastest, most affor-dable and safest way to reduce carbon emissions is to further deploy the world leading biomass technology Drax has pioneered to upgrade more of the UK’s existing coal fired power stations to sustainable biomass.”