NamPower’s N$330 million refurbishment of four units at the coal-fired Van Eck Power Station in Windhoek has come under scrutiny;
amid criticism the project will not improve electricity output from the plant.
According to Switzerland based engineer, Ernst Koller, who worked on the installation of the plant in 1973, the project which is already three years behind schedule, should be demolished to make way for a 250MW gas turbine.
“The building as is could therefore be reused for the installation of the new equipment,” Koller said.
Responding to Koller’s criticism, NamPower Managing Director, Kahenge Haulofu, said the refurbishment has been taking longer than was originally anticipated because the state of certain old components could only be assessed after they were opened up as part of the refurbishment process.
Haulofu this week said most major components have been refurbished to date and only awaiting commissioning. “The refurbishment will be completed in 2018 and Van Eck Power Station will remain on stand-by to assist the Namibian transmission grid during periods of regional power shortages as well as during periods of planned and unplanned outages of other generating assets in the country,” he said.
“The initial three steam turbines that were installed at Van Eck Power Station in the 70s, as well as the fourth turbine that was installed at a later stage, were refurbished along with their respective boilers and ancillary plant.”
Pouring water on Koller’s suggestion, he said to decommission the existing turbines and install a 250MW gas turbine will not make technical or economic sense. He said for a new 250MW gas turbine to be installed, a more suitable location will need to be acquired, which is in closer proximity to a fuel supply source - either natural gas or diesel, among other considerations such as cooling requirements.
“If a gas turbine is installed at Van Eck Power Station, how will the gas be piped to Windhoek and where will it be sourced?”
Haulofu said alternatively, a separate fuel (diesel) supply chain will need to be established in order to cater for the huge amount of fuel that will be consumed. He said this will not make economic sense for NamPower or Namibia to switch from being an importer of electricity to now become an importer of natural gas or diesel for the purported plant.
“The cost of these upgrades will dwarf the cost of the old Van Eck Power Station building, thus making it unfeasible to decommission the existing equipment just to re-utilise the building. An open cycle gas turbine installation is an emergency supply, and with the current cost of fuel one would only want to operate it under emergency conditions,” he said.
The original four turbines (rated at 30MW each) installed at Van Eck Power Station remain in service.
Haulofu said Van Eck Power Station will eventually be decommissioned, with two of the four generators remaining in service to assist with national transmission grid stability. He explained that the plant is being kept as a standby generator plant should there be generation constraints on other generation plants and power purchase agreements contracts, which has not happened in a long time.
The rehabilitation was meant to increase the reliability and efficiency of the power station to meet its original design output of 120 MW. After full refurbishment, each of the four units will generate 30 MW with a lifespan of 10 years.
According to the 2017 NamPower Annual Report released in December, units 2, 3 and 4 are being operated at minimum loads of ±11 MW to support and stabilise the Namibian transmission network.
The report said challenges remain, mainly due to various technical challenges that are being encountered, which in turn affect the reliability and the desired output (30 MW) of the units. This was attributed to the ageing infrastructure of the power station.
“These problems are, however, being attended to and the project is expected to be completed by 2018. Unit 1 still needs to be hot commissioned in generation mode,” the report said.