The Sunday Mail
Senior Business Reporter
The power supply situation in Zimbabwe has improved significantly after the country last week started receiving 400 megawatts (MW) from South Africa’s Eskom, Zesa Holdings spokesman Fullard Gwasira said on Friday.
The imports are testimony of President Mnangagwa’s efforts, after engaging his South African counterpart Cyril Ramaphosa early last month for assistance to alleviate the power situation in Zimbabwe.
Indeed his efforts have paid off.
The State power utility, Zesa, had been facing hurdles convincing Eskom to resume exports to Zimbabwe because of an outstanding debt of US$33 million from previous supplies. Harare has since settled part of the debt.
Under the new power import agreement with South Africa, Cabinet this week made a commitment for Treasury to make available nearly US$1 million weekly towards settling the outstanding debt to the South African power utility and in order to start receiving fresh power supplies.
While the latest imports from South Africa will reduce the gap between demand and supply of power in Zimbabwe, the imports will not completely eliminate planned power cuts, as the water situation at Kariba remains precarious and has forced generation to be scaled further down.
Zimbabwe is facing acute power shortage due to reduced internal generation capacity largely occasioned by fast dropping water levels at one of the country’s anchor power stations, Kariba South, which has resulted in the regulators reducing water allocations for generation of electricity.
Kariba South, following the completion of a capacity extension project in March last year, now has rated capacity of 1050MW, but can hardly produce half the amount due to low lake water levels, with fears abound of potential depletion, following the drought experienced last year.
Zimbabwe, however, needs about 1 800MW at peak periods of demand, but is only currently able to generate an average of 800MW, assuming all generators at its other major power station, Hwange, are working properly.
Other small thermal power stations, Bulawayo, Munyati and Harare, make insignificantly contributions as they are being made to produce despite being decommissioned a long time ago and are awaiting re-powering.
The only viable option at the moment is, therefore, importing from the region, which, however, comes at a great cost given the amount of foreign currency required in a country already facing an acute dollar crunch.
Mr Gwasira told The Sunday Mail Business that they had started receiving power from Eskom, which will see the utility down grading to stage 1 load shedding, but he said this will not eliminate power rationing, as the precarious hydrological situation at Kariba remains a major issue.
Stage 1 loading shedding entails power rationing when the deficit is below 1 000MW while stage 2 involves demand side management when the shortfall exceeds 1 000MW.
“We have started receiving 400 megawatts from Eskom and this will go a long way towards reducing load shedding, but this is coming at a great cost and so we urge all our customers to pay for power so we can initiate other measures to improve supply,” Gwasira said.
Mr Gwasira said the load shedding, which has been going on for at least 18 hours and serious disrupting household, commercial, industrial and agricultural activities, would be more predictable; that is common during peak periods.
Peak periods in terms of demand for power in Zimbabwe occur in the mornings from about 0500 hours to about 0900 hours and during evenings from 1500hrs to 1000hrs. In between these periods the demand us lower.
Mr Gwasira said while all generating units were working well at Hwange Power Station, the reduced output at Kariba from an average 358MW to 272MW to conserve water meant the country remained in a deficit position.
Kariba Dam is designed to hold water at 485 metres when the lake is at full holding capacity, but the reservoir is only allowed to use what is technically referred to as “live water”, which is the water usable for power generation. This water is allowed to drop to a minimum of 475 metres.
Below 475m, the remaining water is reserved for recreational activities, tourism and commercial fishing. Reducing the water level below 475m by continuing to generate electricity poses the risk of depleting the giant lake and making it difficult for the dam to fill up again to a level where it can be used to produce power again in the near future.
In any case, below 475m Kariba Dam cannot effectively discharge its potential in terms of power generation since the water will have less thrust power to drive the turbines that drive the generators to produce electricity.
Kariba Dam’s water is regulated by the Zambezi River Authority (ZRA). The authority also manages the affairs of the Zambezi River for Zimbabwe and Zambia and supplies the world’s biggest man made dam with the water used in the production of electricity.