They failed because Kenyans are siphoning off the oil from transformers and selling to street vendors to use as cooking oil... It lasts longer than regular oil.
Kenyan power companies have been facing difficulties keeping the lights on even in areas that are connected to the electrical grid, as vandals have reportedly been stealing oil from electrical transformers to sell to chefs as cooking oil.
According to Yahoo News, electrical transformers are no great difficulty for determined thieves, who are willing to climb 20-foot poles to get to the transformers and siphon off the oil that powers them. They can then sell the oil for about $12 per liter to chefs at cooking stands who use it to fry food. The oil reportedly looks just like regular cooking oil, but it lasts much longer. It is not exactly edible, though, as the transformer oil contains toxic polychlorinated biphenyls (PCBs), which have been illegal in the U.S. since 1979. But still, chefs are using the stolen oil to make chips and other fried foods.
Dr. Esther Maina, a biochemist at Nairobi University, told Yahoo News that, “Consumption of PCB-laden chips poses a health risk to Kenyans in a country where health services are already underfunded and doctors are in short supply.”
At a loss for a way to combat the problem, Kenya Power is reportedly considering switching to transformers that don’t use oil. The oil-free transformers are much more expensive, but might last longer if no one is trying to pry them off poles to get at their oil.
http://www.thedailymeal.com/thieves-kenya-steal-electrical-transformer-oil-cooking/122814
Well, they're also raiding the transformers for the copper, so that plan won't do much good either.