SYDNEY, AAP – Origin Energy has slumped to a full-year net loss of $2.3 billion after hefty writedowns and has flagged continuing vulnerability in its energy markets business due to lower power prices and higher fuel costs.

The massive loss comes after the power and gas retailer last month outlined impairments of $2.25 billion against some of its generation assets and in relation to a deferred tax liability.

Underlying profit for the 12 months to June 30 slid 69 per cent to $318 million.

Origin, like its peers, has been buffeted by the impact of coronavirus lockdowns on electricity demand, with wholesale power prices sliding amid an increase in rooftop solar generation. It was also hurt by higher gas costs.

“Operating conditions were challenging this year due to low prices and the impacts of COVID-19 across our key commodities of electricity, natural gas and oil,” chief executive Frank Calabria said in a statement.

“Energy Markets headwinds are expected to persist into FY2022, though this should be largely offset by the strong performance of our Integrated Gas business,” he added.

Earnings at its energy market business fell 32 per cent to $991 million, mainly due to lower wholesale prices. The company expects this to slump further this financial year to between $450 million and $600 million before rebounding the following year.

Its integrated gas unit earnings also fell 35 per cent to $1.13 billion due to lower oil prices but could recover in the current year.

Origin will pay an unfranked final dividend of 7.5 cents a share, down from 10 cents a year ago.