Power supply down to the wire

South Africans are cooking up a storm with their energy usage habits, a survey released by Statistics SA yesterday showed.

Nearly eight of every 10 of households use electricity as their main source for cooking, compared with less than six out of 10 a decade ago.

The use of open fires, gas and coal has declined. Only about 20000 households still use animal dung to keep the pots simmering.

According to statistician-general Pali Lehohla, the General Household Survey reflects an impressive rollout of power to the people.

The survey also reveals that about one out of every seven households that pays for electricity reported that supply was prone to interruptions. It was the highest in the North West, where a quarter of respondents complained.

President Jacob Zuma has boasted about connecting more homes to the grid, but the large number of residential users makes the system more vulnerable.

Eskom has a thin margin between the electricity it generates and demand from users.

A cold snap can move residential users to all switch on heaters at the same time, boosting consumption in the peak period between 5pm and 9pm, a time when stoves, ovens and television sets are also in use.

Eskom has targeted these times with advertising and SMS campaigns that ask consumers to reduce their electricity usage.

Despite this, the state-owned power company has had to institute loadshedding on three separate occasions in the past three months, most recently on Tuesday.

Eskom declared another emergency yesterday.

"The national power grid is severely constrained this afternoon, resulting in Eskom declaring a system emergency," the power utility said.

"The constrained conditions are expected to continue tomorrow [today], particularly between 5.30pm and 6.30pm."

The Free State has the highest percentage of households connected to the mains supply, with 91.7%. This is followed closely by Limpopo, Mpumalanga, Northern Cape and Western Cape.

In KwaZulu-Natal, fewer than 80% of households are connected and Gauteng is the second-lowest with 83.6%. Lehohla ascribed Gauteng's relatively low number to the large number of informal settlements.