ESKOM: The way forward

23 April 2014

In recent months, the energy utility Eskom has been plagued by a bout of negative headlines. We will take a look at the reasons behind these electricity blackouts, and the new projects in progress that are aimed at addressing these issues.

With shorter days and cooler evenings we saw the sudden implementation of load-shedding in most parts of the country in March. This brief power outage was a reminder of the widespread rolling blackouts felt in 2008, when electricity supply was overtaken by demand, resulting in widespread electricity shortages and disruptions throughout South Africa. These trying times placed increased pressure on an already fragile economy as large industrial consumers, including mines and smelters were forced to stop consuming electricity and, consequently, halt production. These energy disruptions also impacted on the current account deficit as exports slowed and negative sentiment toward the country and reduced foreign investment caused the currency to weaken further.

Continuous heavy rainfall during March led to excessively wet coal stockpiles at coal mines, and the wet coal contributed to unit failures at Eskom’s Kendal, Majuba and Grootvlei power stations. The explanation is that dry coal contains both inherent as well as surface moisture. When this solid coal becomes too wet, the transportation of the coal poses problems for power stations as it tends to block transfer chutes, preventing the coal from being transferred from one conveyor to another. Apart from hindering the free flow of coal, too much moisture can also result in the clogging of the milling plants and associated pipe work.

Wet coal also requires higher temperatures for combustion to take place, limiting the amount of electricity the power plant can produce. For combustion to happen in the shortest possible time, and within the confinement of the boiler furnace the coal is burned at approximately 90 degrees Celsius, dried out and finally removed from the mills through a blast of hot air. However, if the coal is too wet, the amount of heat energy required to evaporate the moisture is greater than the boiler design allows. This limits the amount of coal that can be dried for the milling process and the pulverized coal that can be fired into the boiler, in turn limiting the amount of electricity that can be generated.

So the wet coal stockpiles being used at power stations paired with unplanned shutdowns at other stations, has led to a significant decrease in our country’s electricity generating capacity. Luckily not all is doom and gloom and Eskom has embarked on various new projects to increase its grid capacity at various intervals over the next few years. Since the concept of renewable energy is also becoming increasingly important globally, Eskom has recognised the need to move in this direction by conducting extensive research with regards to renewable energy sources such as solar power, biomass power, conventional hydro-power, pumped storage, and wind and wave power.

Eskom has embarked on various new projects to increase its grid capacity at various intervals over the next few years.

Some of the energy projects which Eskom has launched in order to increase its grid capacity over the next few years include:

The Medupi Power Station Project

This coal powered mega-station has fallen behind schedule as a result of labour disputes and construction quality concerns resulting in the completion of the boiler falling behind schedule. Fortunately, the project is well on its way to completion and the first 800 MW of electricity (from two boilers), is expected to feed into the grid by the end of 2014. Once the scheduled six boilers are completed, Medupi will have a combined output of 4800 MW of power and is projected to contribute 0.35% towards South Africa’s GDP growth rate per year. This station is expected to become the world’s largest dry-cooled, coalfired power station.

The Kusile Power Station Project

Kusile is a coal-fired power station close to the existing Kendal Power Station in the Nkangala District of the Mpumalanga Province. Kusile is the most advanced coal-fired power plant project in Eskom and the first unit is planned for commercial operation in 2014, with the other units commissioned at approximately 8 month intervals and the last unit expected to be in commercial operation by 2018. This project is on schedule and is expected to meet the planned target date.

The Sere Wind Farm Project

Sere, which means “cool breeze”, is Eskom’s first large scale renewable energy project. The wind farm, which is currently under construction, is expected to reach completion towards the end of 2014 and will ultimately consist of 46 wind turbines of 2.3 MW each, generating a capacity of 100 MW of electricity. This wind farm project is expected to reduce carbon emissions by almost 4.7 million tons over its 20 year life.

The Ingula Pumped Storage Scheme Project

Situated within the Drakensberg range on the border between the Free State and KwaZulu-Natal, Ingula is Eskom’s third pump storage scheme with an output of 1332 MW. The station is expected to be fully operational by the end of 2015 and occupies an area of roughly 14 000 hectares. This mountainous grassland area is managed by Eskom and is in the process of being proclaimed as a nature reserve. This initiative is to compensate for any possible damage to the environment.

Since the rolling blackouts of 2008, the private sector has perhaps become more inventive in addressing the current limitations facing South Africa’s energy utility. Sasol has committed to producing low-carbon electricity in an attempt to reduce carbon emissions and improve energy efficiency. A 140 MW gas-fired power plant at Sasolburg was constructed with gas feedstock coming from the central processing facility in Mozambique. The plant will raise Sasol’s electricity selfsufficiency to 840 MW, or 60% of its overall power consumption, reducing reliance on Eskom power in South Africa. Other mining houses have also adopted energy saving initiatives. Anglo American and BHP Billiton, amongst others have taken on energy reduction programmes where the utilisation of vacuum ice plants, pelton wheel turbines, and mill-power optimisation technology are used to reduce energy demand.

Despite these efforts by the private sector, Eskom will continue to play a crucial role in meeting the country’s electricity requirements. It remains critical that there is timeous delivery on initiatives already in progress if South Africa is to realise its potential GDP growth rate and cement its’ place as one of Africa’s largest economies.