Islamabad, April 30 : Pakistan's Water and Power Development Authority (WAPDA) has devised a plan to increase the hydroelectric energy share in the country's power supply from the existing 9,406 megawatts (MW) to 20,591 MW by the year 2028-29, local media reported on Saturday. The hydropower will be added in two phases, the country's state news agency Associated Press of Pakistan reported, reports Xinhua news agency citing the local media as saying. In the first phase, the share of the hydroelectric energy will be raised from 9,406 MW to 12,366 MW by 2025 and in the next phase, it will be jacked up to 20,591 MW. At present, the hydroelectric energy share in the overall energy mix stands at 31 per cent with an annual electricity power generation of 37 billion units, according to the report. WAPDA, under its electricity generation plan, will add 17 billion units of low-cost hydroelectric energy, raising the number of units from 37 to 54 billion by the year 2025 and another 27 billion hydroelectric units from 54 to 81 billion units by the year 2028-29. /IANS