Many parts of Ghana were plunged into darkness due to a lack of gas to power machinery used to generate electricity in the country.Power distribution firm Ghana Grid Company Limited (GRIDCo) says the situation has caused "a supply gap of 550MW at peak time" at Tema power plant, near the capital, Accra.
This is about 10% of the country's total capacity.
The massive outage started on Thursday evening.
Power has now been restored in some areas but GRIDCo spokesperson Dzifa Bampoh told the BBC there would be more outages on Friday evening, during peak hours.
Ghana is currently going through its worst economic crisis in a generation.There are frequent power cuts in Ghana but this is the worst nationwide outage for two years.
A June study said the country's current energy provision was "critically unhealthy and tottering towards a power crisis".
The power situation, which could worsen in the coming years, has been exacerbated by the country's financial distress, the Centre for Socioeconomic Studies (CSS) study showed.
In July, independent power producers in the country threatened to shut down operations over arrears owed to them by state-run Electricity Company of Ghana.
In a statement on Thursday, GRIDCo, the power operator, said electricity supply to consumers in some parts of Ghana would be curtailed as a result of "limited gas supply" to the Tema power plant.
"The inconvenience caused is deeply regretted," the statement added.
The GRIDCo spokesperson said it was caused by a problem in gas supply from Takoradi.
Some reports say the issue was that gas suppliers had not been paid.
The power utility firm did not say how long it would take for normal supplies to resume.
Ghana has for several years been experiencing power shortages popularly known as "dumsor", which means on and off in the Akan language.
The West African country gets its much of its electricity from hydro and thermal sources, but these are often poorly maintained.
The country has in the last few years become heavily reliant on gas as a major source of energy for electricity generation and any shortage in gas results in power outages. 
https://www.bbc.co.uk/news/world-africa-67236078 
