Eskom is now rationing electricity at stage 6 – here's what that means

• On Monday night Eskom shifted planned blackouts to stage 6 – a new high in electricity rationing for South Africa.
• Nine months ago the company said it was not actually planning even as high as stage 5, but that such high levels of load shedding were only theoretical.
• At stage 8 Eskom estimates that the average South African will be getting electricity for 12 hours every day.
• Here's what Eskom's load shedding stages mean in terms of electricity generated.
• For more stories go to www.BusinessInsider.co.za.

On Monday night state power supplier Eskom announced – at 20 minutes notice – that it would be shifting from stage 4 to stage 6 in its system of electricity rationing. 

Earlier in the day it gave 45 minutes notice before shifting from stage 2 to stage 4 load shedding.

Though South Africa's system for blackouts go up to stage 8, anything above 4 was still strictly theoretical as of March, with Eskom saying it had prepared for stages 5, 6, and 7 load shedding only as a contingency.

See also: This is how much it will cost to take your home off the grid - and avoid load shedding forever

In September the government spread Eskom's promise that the summer of 2019/2020 would see no load shedding at all. 

The shift to stage 6 caught some of South Africa's biggest cities flat-footed, with both Ekurhuleni and Johannesburg telling customers they had no schedules for such an eventuality, and could not say which parts of the cities would be blacked out when.

Meanwhile the Nelson Mandela Bay municipality said it would simply continue to follow its schedule for stage 4 load shedding. 

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.

See also: Abandoned South African mines could become giant batteries to fend off load shedding if a UK company has its way

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