Karpowership, one of the world's largest operators of floating power plants, has agreed a 5-year deal to provide electricity to Sierra Leone's state power utility, the Turkish company said on Tuesday.

Karpowership - part of the Karadeniz Energy Group - already supplies around 80 per cent of the West African nation's electricity via two powerships anchored off the capital Freetown under a contract signed in 2018.

The vessels are dual-fuel powered using either heavy fuel oil or liquefied natural gas (LNG).

The new agreement will add 5 megawatts (MW) to current production. Karpowership will generate an average of 63 MW during the dry season and 23 MW during the wet season for Sierra Leone's Electricity Distribution and Supply Authority.

Karpowership did not release financial details of the deal.

With an electrification rate of just 5 per cent, Sierra Leone's current generation capacity falls well short of the needs of its 7 million citizens. Prolonged blackouts are common even in the capital and urban areas.

Karpowership currently provides around 4,100 MW of power from its fleet of ships, mainly in eight African nations but also in Cuba, across the Middle East and Asia.