Burundi expects to inject an extra 22 megawatts of electricity to its national grid to bridge a supply deficit that has already led to power rationing expected for the next three months, an energy ministry official said on Monday.The central African nation has a total capacity of 42 MW but it is suffering from a 15 MW deficit due to a fall in water reserves in its main hydroelectric dam.The drop in water levels caused the state-run water and electricity company REGIDESO to implement an eight-hour a day power rationing that started last week and is expected to run until October.Godefroid Hakizimana, spokesman for the energy ministry, said the government had in the short term secured a $15 million grant from the World Bank to buy emergency generators to alleviate the deficit by adding an extra 5.5 MW to the grid.He said the government had signed a contract with a Swedish company whose name he would not give, for the construction of a 12 megawatt hydroelectric plant in the west of the country."We think the Swedish enterprise will start construction works by next year, and when the hydroelectric plant will be operational, the company will distribute electricity to REGIDESO, which in turn will sell power to consumers,” he said. Hakizimana said Burundi was also negotiating with the European Investment Bank and the World Bank to get a concessional loan of $210 million to build two hydroelectric plants which can supply 50 megawatts, but did not say when this was expected to be disbursed.The central African nation also signed a deal with a Chinese company for the construction of a 10 megawatt hydroelectric plant, estimated to cost $45 million, he added, saying the two projects will take between four and five years to complete.Water and electricity tariffs have been doubled since September last year, and authorities said the measure was taken to enable the state water and electricity board (REGIDESO) satisfying the increasing demand.Only 3 percent of the population has access to electricity, while demand for it grows by 13 percent every year.