SIKI MGABADELI: You will have seen the article written by Chris Yelland on the Moneyweb website where he argues that the new technical problems arising during the commissioning of Unit 6 at Medupi – the first of six 800 megawatt generation units at Eskom’s Medupi power station – may be placing South Africa’s electricity supply at risk.
Chris Yelland is investigative editor at EE Publishers and joins us now. Chris, thanks for your time this evening and happy new year. What are these technical problems – for those of us who don’t understand the stuff?
CHRIS YELLAND: Well, you may recall that Eskom is the process of commissioning the first generation unit at Medupi power station, which is known as Unit 6, strangely enough. Unit 6 is undergoing commissioning and has been experiencing some problems in commissioning which have caused yet further delay.
You may remember that the first synchronisation of Unit 6 was supposed to take place at the end of 2013, with the famous Malusi Gigaba’s “heads will roll” statement. Of course it didn’t take place then and it was delayed until December 24 2014. It was subsequently delayed until the middle of January, and we’ve just heard today that it has been delayed until the end of February. We certainly hope it’s not going to be delayed further, because we all know that it’s an important milestone along the way towards commercial production of power at the first unit at Medupi, which is scheduled for the middle of 2015. So these new technical problems have resulted in yet a further delay and they’ve also added a whole lot of new risks to the equation.
SIKI MGABADELI: OK. Firstly, just explain in as simple language as possible what the technical issue is.
CHRIS YELLAND: Well, before you can connect steam to the turbine, which is the thing that drives the generator, you need to make sure that that steam coming out of the boiler is clean. During the construction process there is lots of welding and activity around the boiler, and various rubbish and dirt and particles and chunks of metal and welding rods accumulate inside the boiler. And before you can connect the boiler to the turbine you need to clear all this rubbish out of the boiler. It varies in size from chunks of metal down to small particles and even scale on the steel. To do this, Eskom fires up the boilers, they build up the steam and then they blast the steam off through a pipe to the atmosphere instead of through the turbine. In this process they are basically blowing through all the dirt out of the boiler to the atmosphere.
They do this process repetitively over a period of several weeks, where they fire the boiler and blast the steam at high speed and in great volumes and great turbulence of steam to blast this dirt out. It’s a process that’s done in accordance with strict technical guidelines because it impacts on the turbine and can cause damage to the turbine if it’s not done properly. So it has to be done very rigorously and properly, and under strictly controlled conditions of steam speed and pressure and temperature which really simulates the full-load operating conditions of the boiler. You’ve got to get it so that it is doing this as though it was operating normally at full-load conditions so that any dirt that would pass through to the turbine under normal full-load condition is now vented and got rid of.
Well, the problem has been that Eskom has been simply unable to achieve the specified levels of steam speed and steam volume and steam turbulence in doing these tests. In other words, it’s been doing these tests at levels below those specified and it cannot achieve the right specified level, which means that it’s not able to blow through the kind of dirt that would normally blow through under normal full-load operating conditions. And the fear of course, is that when you do connect it up and operate at full-load conditions, which are at higher levels of steam speed, then the real burden is going to come through and this could damage the turbine.
So that’s the fear. It hasn’t been done to the specification and for technical reasons Eskom simply cannot achieve the required steam-speed conditions necessary to do this test. And therefore it’s failing in the technical steam-quality requirement specified in the contract. The manufacturers of the turbine and the steam valve, which are all critical items in this whole process, are basically saying, guys, you are not doing this test to the spec, and therefore how can we guarantee our equipment. And that’s the risk.
SIKI MGABADELI: OK. So worst-case scenario here is what?
CHRIS YELLAND: Because Eskom has decided that they cannot do these tests, they have decided to abandon them and connect up the pipe work to the turbine and proceed with commissioning. Now they’ve done what they call an “intensive risk analysis” and they have determined in their wisdom that in fact the risk is very low and the need for getting these generators on stream is very high.
The cost to the economy if we don’t get these generators on stream is very high, and they’ve done a sort of risk/benefit analysis and decided to take the risk. They say that the risk they have determined in their wisdom is very low.
But you see, the real risk, even though they may decide that the risk is very low, the real risk is they are going to lose the guarantee on the turbine and the steam valve, and they are going to have to bear that risk; the guarantee risk that would normally be passed on to the manufacturer is going to be borne by Eskom. That is a serious commercial and technical risk.
SIKI MGABADELI: Thanks to Chris Yelland.
• Subscribe to a daily email of transcripts from Moneyweb Radio – click here