Why no daylight savings in ZA?

According to the US has significant enrgy savings through their implementation of daylight savings. I never thought of daylight savings as an energy saver, but it must be true. Here’s the excerpt:

How Does Daylight Savings Time Save Energy?
Theory has it that daylight savings time promotes energy conservation. According to the California Energy Commission, energy use and the demand for electricity for lighting homes is directly connected to bedtime. When people go to bed, they turn of lights, TVs and other appliances, which account for about 25 percent of America’s daily total use of electricity.

Studies done in the 1970s by the U.S. Department of Transportation show that America’s electricity usage is reduced by about one percent during each day that daylight savings time is in effect.

I’m definitely not the biggest fan of early rising, and daylight saving would throw me off for at least a week, but surely energy saving is a good enough reason to have daylight saving in South Africa?