Hwange expansion to tame power imports…345 km transmission line, 250 000 cubic metre reservoir push US$1,4 bn project to completion

Mashudu Netsianda, Senior Reporter 

Transmission and distribution works on the US$1,4 billion Hwange Thermal Power Station Unit 7 and 8 expansion project are nearing completion with a 345km transmission line and a new 250 000 cubic metre reservoir having been constructed.

Projected to inject an additional 600 megawatts to the national grid, the first unit of the project is set for commissioning in November this year with the remainder coming on board in the first quarter of 2023.

The country’s power generation capacity is subdued at around 1 300MW with demand hovering around 1 750MW, according to official statistics.

Currently the commissioning of Unit 7 auxiliary systems is ongoing with systems such as the water supply to the boiler, auxiliary boiler, fire protection system and auxiliary transformers having been commissioned. 

When fully commissioned, the project will help Zimbabwe tame electricity imports and drive increased industrial production with guaranteed electricity, which is a key economic enabler. 

The Hwange Thermal Power Station Unit 7 and 8 expansion project is one of the flagship projects being implemented under the Second Republic in line with Vision 2030, which aims to transform Zimbabwe into an upper middle-income economy.

The project began in August 2018 following a ground-breaking ceremony by President Mnangagwa while the main construction of two additional coal-fired units of 300MW capacity each was started in March 2019.

The power station is expected to generate more than 60 percent of Zimbabwe’s electricity needs following the expansion.

The project is funded by China Exim Bank and is being executed by Sinohydro and the Government of Zimbabwe through the Zimbabwe Power Company (ZPC) and is expected to be a game-changer in terms of enhancing power supply in the country.

In an interview yesterday, the ZPC project manager Engineer, Forbes Chanakira said they have completed 345km of the transmission line meant to take the generated power from the plant to the distribution points.

“The commissioning of Unit 7 auxiliary systems is ongoing with the water supply to the boiler, auxiliary boiler, fire protection system and auxiliary transformers having been commissioned. The Unit 7 is expected to be started up in November 2022 with all systems in place,” he said. 

The commissioning of the various plant auxiliaries is a pre-requisite to the running of the main units, which are expected to be in full operation in February next year.

The water treatment plant is one of the major components in the generation of power as it is responsible for turning the turbines.

Water coming from the treatment plant goes into the boiler and is heated to form steam.

“The moment the water is converted into steam it goes through various super heaters which increase the temperature of the water to around 540 degrees Celsius and 17 mega pascals at which point it will be considered as dry steam, which is then sent to the turbines side,” said Eng Chanakira.

“The turbines are then turned by the steam. The turbine then turns the generator resulting in electricity as the output of the whole process.”

Eng Chanakira said while the daily water demand for Unit 7 and 8 is 1 860 cubic metres per hour, a new 250 000 cubic metre reservoir to complement the existing one has been constructed as part of the expansion project.

“However, works at Unit 8, which is three months behind Unit 7, is expected to be commissioned in February 2023. The transmission and distribution works to facilitate evacuation of generated power from Units 7 and 8 are almost completed and we have covered 345km of transmission line of a total of 368km,” he said.

Eng Chanakira said the main challenge that delayed the project was Covid-19 which at its peak affected the design of various systems and manufacturing as most factories were closed across the world. 

“Covid-19 also affected us in terms of logistics as we could not get delivery of various equipment and material. We also could not be able to mobilise the original equipment manufacturers as well as experts to support the construction works in Zimbabwe,” he said.

“Notwithstanding these challenges, the contractor Sinohydro remained steadfast and pushed the project despite those Covid-19 related challenges. Our ZPC team also continued with the work despite the risk and that is why we managed to cover a lot of ground.” 

Eng Chanakira said the project has generated employment for more than 4 000 locals.

“More than 4 000 local people have been employed directly by the project and in excess of 3 000 have been employed indirectly including subcontractors, suppliers of goods and services,” he said.

Eng Chanakira said the project will see more than 400 families from Hwange’s Ingagula suburb situated near Hwange Thermal Power Station being relocated. 

“The affected households will be compensated in line with our relocation action plan approved by the Environmental Management Agency (EMA),” he said.

The Ingagula is exposed to pollution due to its proximity to the power plant. The suburb has been in existence for decades with residents enduring air and land pollution from flue gas. 

“The amount of discharge will be extreme after the completion of Units 7 and 8 hence the need to relocate the families. The thrust is to relocate all people from Ingagula to a new housing area where more than 600 houses will be constructed,” said Eng Chanakira.

“We are constructing 74 houses for people who will be affected along the new powerline, and 13 have already been handed over to the beneficiaries in Epping Forest. However, the estimated relocation cost is yet to be finalised.” 

EMA gave ZPC an ultimatum to relocate Ingagula residents before commissioning the expansion project.

Article Source: The Chronicle