A Nigerian businessman who controls 15% of the country’s electricity market has called for an overhaul of the grid to solve long-running problems with supply. Tony Elumelu, who controls several power sector companies, told Bloomberg in an interview that Nigeria needs more transmission lines and the electricity market needs more liquidity in order to reverse years of insufficient supply that is hampering economic growth. “As a country, we can’t produce well enough in spite of our natural resources. The reason is lack…