Solar power: Cheap energy source for Africa

Kerosene lamps and sore eyes were once routine elements of grading student homework. Solar electricity has changed that. Caroline Hombe, a 35-year-old teacher in rural Mhondoro, Zimbabwe, can go through the pile of books stacked on her table without worrying that the onset of darkness will put an end to her work. African countries, blessed with sunlight all year round, are tapping this free and clean energy source to light up remote and isolated homes that have no immediate hope of linking to their national electricity grid.