Power utility Eskom on Wednesday called on consumers to switch off geysers, pool pumps and all non-e.
Judge Ellen Francis ruled that Ehlers must be restored to the same position she had at the time of her dismissal.
However, she dismissed Ehlers' claims for damages.
The court ruled that her employers will also be required to apologise to her within one week.
The company is also required to prevent discrimination against Ehlers and other people in the workplace.