What Happens to the Grid During Load Shedding?

As South Africans face a repeat of the 2008-2009 electricity crisis, and the implementation of rolling blackouts through load shedding, it is important to understand what load shedding is, and how it affects the power grid, and hence our economy and our lives. Find out…

SA Oil explains what happens to the grid during load shedding

What is Load Shedding?

Load shedding is a controlled, preventative measure implemented during times of greater strain on the power grid, when the demand on the system is more than the grid can supply. It is done country-wide, both to those who receive power directly from Eskom and from municipalities and it aims to prevent a national power blackout – which, if a blackout occurred, would mean weeks in darkness while Eskom attempted to restore full power.

Why Does Load Shedding Happen?

South Africa makes use of one electricity supplier – state-owned Eskom. The parastatal reintroduced the implementation of load shedding late last year, blaming its decision on poor maintenance of its power stations, as well as large-scale malfeasance. Load shedding can also be caused by poor-quality coal, or insufficient amounts of coal – with which the parastatal announced its struggle last year. The result is load shedding, forcing the demand of electricity down so that Eskom can still provide some electricity during ‘up’ times. During ‘down’ times, technicians are working on fixing broken machinery, or catching up on maintenance, or the provider is making provisions to obtain more fuel sources, such as supplementary coal or interim fuels like diesel and HFO.

Load Shedding Around the World

Load shedding is not a concept or occurrence unique to South Africa – many countries around the world have to deal with similar conditions. Even in North America, considered a developed country, citizens face the chance of power cuts during hotter months when storms are seen more frequently and when the grid faces a higher demand – known as brown-outs, this is a possible yearly incident with which Americans, and many other countries, have to deal.

How the Grid is Powered Up After Load Shedding

Many of us refer to Eskom’s ‘switch’ – the notion of Eskom flipping the power on and off with a switch according to our load shedding schedules. Unfortunately, this is not the case and the process of powering the grid down and then up again is far more complicated than we realise. In the event of a total blackout, many countries are able to rely on neighbouring countries to send some of their surplus electricity to the country in need, to restart their power stations and help start the grid back up. In South Africa, we are unable to do this as we are the only country in Africa which produces the amount of power we need and consume. Thus, Eskom has to rely on other sources and start the system from scratch, powering up one plant at a time, and as such, one area of the country at a time.

Using a Black Start After Load Shedding

In the case of a total blackout, without the availability of outside sources to power up our power plants, Eskom would need to initiate a black start – the process of restoring a power station to full operation without using external power sources. When the entire grid is out of power, more than one black start may take place to bootstrap the grid, which in itself could take two-three weeks, electricity expert Chris Yelland has stated.

To bootstrap a power plant, a small diesel generator is usually used which starts up a larger generator, which then operates the equipment usually powered by some of the electricity generated in a power plant. After receiving this bootstrapped power, a conveyor belt can then begin feeding coal (in the case of most of South Africa’s power stations) into the furnaces again, slowly restarting the power plant section by section. Eskom indicates a period of 30 minutes after load shedding has ended during which they are starting to repower the grid network in the least potentially risky way. Thus, it’s not a case of just flipping a switch back on once the power has gone out – a plant needs an operational generator, the fuel to power the generator, and operational equipment, long before it can start powering up the grid again and supplying citizens with power.

Reliable Fuel Suppliers During Load Shedding

The scenario South Africa faces now highlights the need for back-up fuels – fuels like diesel and HFO – to power generators when the grid is inaccessible, or to use in power stations when standard fuel sources, such as coal, are unavailable. Equally as important is sourcing such fuels from reputable suppliers which offer superior quality products – get the fuel you need to stay switched on during load shedding by contacting us today.