KIM HARRISBERG LIKE many students preparing for exams, Lindokuhle Mdlalose has been revising in the early hours of the morning and losing out on sleep. However, the 21-year-old's midnight study sessions are by necessity, not choice, as power cuts cripple South Africa. The country's worst electricity blackouts in more than two years, intended to take pressure off the creaking power grid after worker strikes and years of poor maintenance, have left households struggling during several hours of darkness each day. Those that can afford extra internet data, generators and solar panels are managing to cope, but for many, their studies,…