Paul Nyathi|ZESA is implementing prolonged load-shedding of up to 18 hours a day following a fault at Hwange Power Station yesterday afternoon.
The power utility said it was moving to Stage 2 load-shedding.
According to Zesa, Stage 1 load-shedding happens to the first group of customers as listed on its schedule and these are switched off as the power shortfall will be within planned limits.
In the event that the power shortfall increases beyond the planned limits, load shedding will move to Stage 2.
Zesa said while it was importing electricity to augment national supplies, power would remain constrained.
“While all efforts are being made to improve the power supply availability through imports, the supply situation remains fragile,” said Zesa.
“Customers are advised to use the available power very sparingly and will be updated as the situation improves. The inconvenience caused is sincerely regretted.”
The first two stages at Hwange Power Station suffer frequent breakdowns because of skipped and skimped maintenance and refurbishment over the past 35 years.
Hwange and modest imports from South Africa and Mozambique have to carry the Zimbabwean load because the regional drought has severely limited output from Kariba South, the largest station.
Kariba, Zimbabwe’s largest power plant with a capacity of 1 050MW, is churning out less than 10 percent of its capacity as water levels at the lake, where neighbouring Zambia also draws water for its power plant on the northern bank, are fast dwindling.
At peak periods of demand, the country requires about 1 800MW, but is currently able to produce an average of 500MW, at best, due to the effect of drought on Kariba water levels and the antiquated equipment at Hwange Power Station.
Given that water levels in the Kariba dam only reach peak inflows around middle of each calendar year when plains up north where the river originates will have saturated, the dam may not supply power for more than half the year in 2020.
Two brand new large boiler-turbine-generator units are being commissioned at Hwange, but the extra 600MW will not start coming on stream until mid-2021.
Hwange is also operating with critically low stocks of coal due to reduced feedstock supplies from the miners amid concerns that the situation could also trigger stoppages of power production.
Recently, Zesa claimed that it was not getting enough supplies from the coal miners — Hwange Colliery, Makomo Resources and Zambezi Gas.
Its target stock is 300 000 tonnes, which is equivalent to 45 days of power generation at 600MW. But ZESA is only receiving an average of 85 000 tonnes, enough for only 11 days.
Importing power is also a challenge as some of the regional suppliers, particularly Eskom of South Africa, are struggling to keep generating units in service. A scarcity of foreign currency has also resulted in Zimbabwe struggling to pay for power imports.
Additional reporting: State Media