Millions across Africa live without access to the grid. A businessman from Nairobi has a plan to change that, but first he wants you to turn off the lights. If it’s currently daytime where you are, please don’t read this. At least, not for now. Rather, if you can, take it home, turn off all the power in your house, and read by the light of a candle. Not easy is it? And notice the silence. No hum of the fridge, no TV, no hot plate, no air-con, not even a radio.