Electricity consumers already crying over high and indiscriminate tariff should brace up for more pain as Nigeria plans to increase electricity rates by as much as 40 percent for some customers next month as a fall in the value of the naira and rising costs hinder efforts to end daily blackouts in Africa’s largest economy.

“We are working on the numbers and going through the processes,’’ Sam Amadi, chairman of the Nigerian Electricity Regulatory Commission, said in a phone interview late Wednesday from the capital, Abuja.

Some bills will increase 5 percent while others will see prices raised as much as 40 percent depending on the power provider and class of customer, he said. The change in rates will take place by mid-November.

According to BloombergBusiness report, monitored in Lagos on Thursday,  Nigeria dismantled its power monopoly and sold 15 state generation and distribution companies in 2013 to private investors in an attempt to end the crippling electricity shortages.

Generated output has never risen above 5,000 megawatts, which is about a third of peak demand, while the state-owned transmission system can’t deliver any more than that before it starts breaking down.

Efforts to boost power supply have been hampered by factors including gas supply, foreign exchange and inflation, that have increased the cost of energy and infrastructure for the power companies, Amadi said. “The law provides for periodic price review when the cost profile changes.”