The bank says an average Nigerian consumes four times less energy than their counterparts in a typical lower middle-income country.
Epileptic power supply costs businesses in Nigeria about $29 billion yearly, the World Bank has said.
The bank's conclusion was drawn from its Power Sector Recovery Programme factsheet presented during the World Bank's virtual meeting with journalists Wednesday.
The bank's practice manager, West and Central Africa Energy, Ashish Khanna, in his presentation said, "Businesses in Nigeria lose about $29bn annually because of unreliable electricity. Nigerian utilities get paid for only a half of the electricity they receive."
According to him, for every N10 worth of electricity received by distribution companies, about N2.60 is lost in poor distribution infrastructure and through power theft and another N3.40 is not being paid for by customers.
"Six in 10 of registered customers are not metered, and their electricity bills are not transparent and clear. This contributes to resistance to pay electricity bills," the PUNCH quoted him as saying.
The PSRP document said only 51 per cent of installed capacity was available for generation, as an average Nigerian consumed four times less energy than their counterpart in a typical lower middle-income country.
The document said the Nigerian government assisted poor citizens in paying up the electricity bills. It said poor citizens use less electricity, while the richer families consume more power.
The bank described the document as a comprehensive response to Nigeria's power challenges with the aim to renew the country's economy by rebuilding a functioning and fair power sector.
The senior energy specialist, World Bank, Muhammad Wakil, said: "Nigeria now has the largest number of 'unelectrified' people globally and the trend is worsening. Of the electrified, the supply is very unreliable with widespread blackouts."
He also said Nigeria now has 25 per cent more "unelectrified" people than the second most unelectrified country in the world, the Democratic Republic of Congo (DRC).
Between June 2020 and February 2021, the World Bank said its board approved $1.25 billion financing to support the Nigerian government in its efforts to reset the power sector.
In 2019, it said 80 million people in the country were without access to electricity and millions more suffered from poor service.
Last June, the bank released a similar report on the economic loss caused by unreliable power supply in Nigeria, which it estimated at N10.1 trillion annually.
The Minister of Power, Saleh Mamman, last week apologised for poor power supply in the country.
Mr Mamman's apology came weeks after many Nigerians had complained of persistent outages. He said some 17 power plants had operational problems.
Malfunctions are common in the sector and often result in extensive blackouts across the country. The government cites gas supply issues despite Nigeria being one the world's largest producers of gas.