Officials in Cuba said power had been restored to around a fifth of residents in the capital Havana on Sunday evening following a two-day nationwide outage.
The island-wide blackout was the fourth in the last six months.
In a statement on social media, the Ministry of Energy and Mines blamed a failure at Cuba’s largest power station, which has yet to be brought back online.
It has since fired up another large station to gradually restore power to the eastern provinces.
In an update to its travel advice issued on Saturday, the Foreign Office urged British visitors to take precautions such as conserving water, fuel and mobile phone charge.
It added: “The mobile phone network may be limited. Transport may be affected due to inability to refuel during the power outage. Ensure you have enough fuel before setting off on your journey.”
The Cuban government is thought to be collaborating with China to develop large solar farms to reduce reliance on its existing oil-fired system.
