Guernsey's electricity prices may rise after a fault with an undersea cable led to the burning of more fossil fuels to generate power.
The cable fault occurred in October 2018 and the use of diesel generators for longer than expected saw Guernsey Electricity spend an extra £6.5m.
This was part of a £7.8m operating loss in 2018/19 for the States-owned firm.
Chief executive Alan Bates said: "We do need to pass these [costs] through, we do need to pay for [what] we use."
He said: "How it is passed through to customers is something we need to discuss with the regulator."
The cable fault meant it operated at lower capacity and the company was only able to import 55% of the island's supply needs - compared to more than 80% in previous years.
Besides the cable fault, which limited the amount of energy that could be imported from France, the increase was put down to a 2.2% fall in electricity usage - equal to a £1.6m loss of income.
The cable has been replaced with a new one, which has been laid and is due to be connected to the Channel Islands Electricity Grid later this month.
Power cuts also increased with the average loss of supply rising from 18.34 minutes in 2017/2018 to 66.81 minutes in 2018/19 - although the major reason for the rise was the initial failure of the cable.