eBusiness Weekly
Martin Kadzere
While it has been highly anticipated that Units 7 and 8 will bring additional capacity to the Hwange Thermal Power Plant, the situation on the ground suggests otherwise.
Generation at the country’s second-largest power plant continues to run, at best, at an average of 40 percent of its designed capacity of 920MW. This week could have probably been the worst after output dropped to 77MW or 8,2 percent of its potential, leaving customers enduring power cuts lasting for more than 15 hours.
In less than a week, from February 15 this year, four generators were taken off after developing problems. The other unit was switched off in October last year and during the better part of this year, the plant was running with only one generator.
According to a general supply summary by the ZPC, Unit 4 was switched off on 15 February after developing a boiler tube leak. Unit 1 was taken off on February 24 after a high-pressure fan got damaged. Unit 3 was stopped on February 24 after developing a tube leak while Unit 6 was switched off on February 23 after developing a similar problem. Unit 5 tripped in October 2021 due to excessive turbine vibrations. From the breakdowns, it’s clear that the plant can no longer be managed.
And as for unit 7, since September last year it is yet to be put on grid.
According to statistics from the Zimbabwe Power Company, a generation unit of ZESA, the average weekly supply stood at about 1 000MW against the demand of 1 600MW, leaving a gross shortfall of 600 MW during peak periods. To put this into perspective, a shortfall of this magnitude amounts to switching off Harare and Bulawayo.
It is apparent that the breakdown frequency of Hwange means managing the plant is becoming more and more difficult. The plant has become so unreliable and any suggestion that Units 7 and 8 would bring additional capacity could be far-fetched.
“Ideally Units 7 and 8 should be adding 600 MW to the exiting capacity but the problem is the frequency of breakdown of the existing plant,” Gerald Tasara, an energy expert said; “Most of the units have already have reached the end of their life span.”
“What will be churned out by the two units will be effectively replacing the current capacity and this won’t make any big difference in terms of delivering additional energy onto the national grid. This won’t make any big difference in terms of the national power supply. However, we can take comfort from the dependability or reliability of the new units as this may stabilise the power supply situation.”
False starts
The new units were scheduled to start operation in November last year, according to official timelines, but the launch has been delayed due to unspecified technical glitches. Undeniably, the process of commissioning projects of such magnitude takes time but authorities hope for a breakthrough in a fortnight.
The Hwange Power Station comprises six existing coal-fired units including four 120 MW units commissioned between 1983 and 1986 and two 220MW units commissioned in 1987. All the units have outlived their life spans by at least eight years.
ZESA chairman Dr Sydney Gata while addressing journalists on a tour of Hwange Power Station sometimes back, said the station was still running because of the local engineers’ ingenuity.
“The plant is too old; it has reached its design life. The plant is now 38 years old, and its designed life is 30 years meaning we are eight years over its designed life,” a ZESA official told a local news agency in September last year.
Energy and Power Development Minister Soda Zhemu said the next step after commissioning Units 7 and 8 was to decommission the existing plant and rebuild a new facility.
He said ZESA has secured a US$310 million facility from India to rebuild Hwange plant.
