Eskom may implement Stage 6 load shedding again on Tuesday night.

Stage 6 “is not confirmed as we speak” for Tuesday night, said Eskom chief operating officer, Jan Oberholzer during an emergency briefing but “the risk is significant”.

If Stage 6 is implemented for a 24-hour period, most people will find themselves without power for six hours on that day, Oberholzer said, though that may be split into blocks of two hours.

Eskom said an already constrained electricity system was being brought to its knees by unlawful and unprotected industrial action at several power stations.

Eskom implemented Stage 6 in December 2019, a level of electricity rationing that had, until then, been strictly theoretical.

At the time, Eskom provided 20 minutes notice for the shift between Stage 4 (the current stage now) and Stage 6.

Operational plans have been made for load shedding up to Stage 8, as a contingency measure should that become necessary to prevent a national blackout when demand exceeds supply, taking down the grid entirely.

Here is what the different stages of load shedding mean.

At every stage of load shedding, Eskom rations the country by a further 1,000MW of power, the equivalent of 1,000,000 kilowatts (A microwave or kettle uses around 1 kilowatt, so one way to think of the stages is that at every escalation, Eskom switches off a million kettles.)

At Stage 1, South Africa as a whole is forced to save 1,000MW, or a million kettles, which – depending on the choices of local governments – mean either short outages for individual electricity users or blackouts in only small parts of cities.

At Stage 2 the national grid is short 2,000MW, or two million kettles, at stage 3 rationing reaches 3,000MW, and so on.

How suburbs and towns are affected by every stage depends on a range of factors, including what time of day the electricity emergency is declared. The exact social and economic impact is hard to estimate, and guesses range widely .

However, by Stage 4 the shortage is equivalent to nearly the full installed generating capacity of the giant Medupi power station – which it is now estimated will cost R18 billion to complete.

At Stage 5 Eskom is unable to supply as much electricity as South Africa has committed to buying from the giant Inga 3 hydropower project in the Democratic Republic of Congo – after doubling its initial offtake intention – and at Stage 6 the rationing is the equivalent of all the power Ethiopia hopes to generate by harnessing the Blue Nile.

Stage 7 sheds as much electricity as all South Africa’s initial 47 independent producers of renewable energy produced.

At Stage 8, Eskom estimates, the average South African will be supplied with power for 50% of the time, with connections turned off for 12 hours out of every 24.