Zesa decommissions three thermal stations

Zimbabwe's power utility, Zesa Holdings, has begun the process of decommissioning three small thermal power plants due to their deteriorating conditions and rising operational costs.

According to Energy and Power Development Minister Edgar Moyo, the decision to decommission the thermal power plants was largely driven by the plants' age and the escalating costs of running coal-fired generators.

These factors have rendered the thermal stations in Harare, Bulawayo and Munyati increasingly unsustainable and inefficient.

"The thermal power plants with a combined capacity of 240 megawatts (MW) ceased generating electricity between July and September 2023.

"The decommissioning decision was made in October last year, and the process is now underway," said Minister Moyo.

"At an average age of 75 years, the thermal plants significantly exceed their intended lifespan of 25 years, and operating them has become financially unsustainable.

"The running cost of Bulawayo station, for example, had ballooned to roughly 46 US cents per kilowatt-hour, making its continued operation unviable."

Minister Moyo further noted that the country's poor rail infrastructure also contributes to rising operational costs, as transporting coal by road becomes increasingly expensive.

Minister Moyo highlighted the challenges of repowering the power stations for extended life due to limited access to funding for fossil fuel projects in light of climate change concerns.

Minister Moyo acknowledged that while decommissioning is necessary, the Government was exploring alternative uses for the facilities.

However, he declined to elaborate on the specific options under consideration.

Harare Thermal Station One was commissioned in 1942 with a design capacity of 21MW but was decommissioned in 1970. Station Two had an initial capacity of 75 MW when it was commissioned in 1955, but it was de-rated to 20 MW due to uneconomical units.

With a capacity of 60MW, station three consists of pulverised fuel-fired boilers.

The station also has two large turbo-alternator machines producing 30MW each. Stations two and three operate independently, but they are linked electrically through four interconnector transformers.

Presently, the dependable capacities for stations two and three are 20MW and 30MW respectively.

The Bulawayo plant was commissioned between 1947 and 1957. While Bulawayo Power Station initially had an installed capacity of 120MW, a refurbishment exercise in 1999 on the aging plant gave it a new lease of life. The station capacity is now 90MW.

Munyati Power Station is situated 5km off the Harare-Bulawayo Road at the 183-kilometre peg. Built in stages between 1946 and 1957, the thermal station originally had a capacity of 120MW but currently operates at a capacity of 100MW.

Although the decommissioning coincides with the ongoing power shortages, the impact is expected to be minimal considering the plants' recent erratic performance and dwindling contribution to the grid due to frequent breakdowns and coal shortages.

"While the timing may seem inopportune given the existing power shortages, decommissioning these aging, inefficient plants is a crucial step towards a more sustainable and cost-effective energy future for Zimbabwe," said a former engineer with ZESA.

"When you analyse the power plant's cost per kilowatt per person reveals its inefficiency, highlighting the rationale behind its decommissioning."