/ 12 July 2013

Gas-powered plant shows the big players how it’s done

Gas Powered Plant Shows The Big Players How It's Done

On July 10, Sasol unveiled the country's biggest energy plant using gas engines. The Sasolburg Gas Engine Power Plant took 1.4-million man-hours to complete. It houses 680 tonnes of steel, 170km of cable, and 10km of piping and ducting.

Its output capacity is enough to supply 200 000 households, a city about the size of Bloemfontein. It's a sizeable undertaking, by all accounts. But compared with Eskom's coal-fuelled Medupi, it's positively bite-sized.

Costing R1.9-billion, it has an operating capacity of 140 megawatts (MW). The plant houses 18 gas engines, each with roughly 10MW of nominal output. Though it is touted as having a production capacity of 140MW, its current output is 175MW. It sells the surplus 35% to Eskom.

The energy the plant generates allows it to power 60% of its own operations and it buys about 40% of the remaining power necessary from the power utility. At the official inauguration of the site, a beaming Henri Loubser, managing director of Sasol New Energy, thanked everyone who was involved.

At one point during the undertaking, Erich Meyer — the portfolio executive of clean energy at Sasol Technology, who managed the project — had asked to discuss project timelines with him.

"I said: 'We can tell them that we can't [finish the project within the time we agreed to], but that wouldn't seem very clever,'" said Loubser.

The result?
The project took 15 months from its inception in July 2011 to starting operations in December 2012. That was three months ahead of schedule. It also came in nearly 20% below budget.

"It's not very often you can tell the board that the project was completed early and came in under budget," said Loubser. Those behind Eskom's mammoth Medupi plant certainly don't know the feeling.

Two days before Sasol's announcement, Public Enterprises Minister Malusi Gigaba made an announcement of his own.

Eskom's flagship power plant, Medupi, would not see its first power unit come online until the middle of next year, rather than the end of December as anticipated.

Delays, including labour unrest and bad workmanship, would push back the entire project by between six months and a year.

The extended time frame will also push up project costs. The original estimate of R91.2-billion has been revised to ­R150-billion (See "Gigaba's power-station stalemate", Page 16). That's a 64% cost increase.

Medupi power plant
The Medupi power plant will have an operating capacity of 4 800MW when complete. That's more than 10% of South Africa's current output of 40 000MW.

It's also more than what is generated by the entire economy of Nigeria. But, Sasol executives pointed out, the comparatively compact gas-engine project had its upside.

"Gas-powered plants require less time to build and install, taking between 20 and 30 months as opposed to the 40 to 50 months required for a coal power plant and 60 to 80 months for a nuclear plant," the company said in a statement.

Then there's the question of set-up costs. Medupi's newly bolstered price tag works out to a cost of more than R31-million a megawatt. Sasol's gas-engine power pans out to R13.5-million per installed megawatt, less than half its counterpart.

According to Sasol, running costs in the two plants will follow a similar pattern.

"The plant does have lower running costs compared to a coal-fired power station," said Alex Anderson, group media manager at Sasol.

"There is no by-product to dispose of and there is less equipment — and therefore less to maintain."

Big may be beautiful, but it appears small is cheaper and quicker: two traits that could sway the views of many a beholder.