Ambuklao-Binga

completed

The proposed IFC investment will partly finance the privatization and rehabilitation of the 75 MW Ambuklao hydroelectric power plant and the 100 MW Binga hydroelectric power plant, currently owned by National Power Corporation (NPC). The rehabilitation will re-commission the Ambuklao plant, which has been shut down due to silt problems, upgrade the Binga plant, and increase the combined capacity by 50 MW in total (30 MW for Ambuklao and 20 MW for Binga) from 175 MW to 225 MW. They will operate as peaking plants, supplying power to the Luzon grid for about five hours daily. There are no electric transmission system constraints with regard to the expected higher generation levels.The project company, SNAPB, is expected to take over the hydropower facilities in June 2008, and will put in place new management procedures, address technical issues such as sedimentation and dam safety and implement the rehabilitation of both plants. SNAPB will also enter into a separate agreement with the Government, for those facilities that will remain under public ownership, to cover the operation and maintenance of the dams and appurtenant structures, formulation of operations manuals, formation of an oversight committee, and maintaining the integrity of the water levels in the reservoirs. Responsibility for the watershed management will remain with the Government.Ambuklao and Binga are located on the Agno River in Benguet Province, in a relatively narrow, steep sided valley. Ambuklao dam was built in 1956, and is of rockfill construction with an impervious central core, maximum height of 129 m, a crest length of 452 m, and a reservoir area of 7.5 km2. The plant was decommissioned in 1999 as a result of accelerated silt accumulation around the water intake point. As part of the rehabilitation, SNAPB will construct another intake point at a higher elevation. The rehabilitation plan will also include installation of new electrical and mechanical equipment and a new tailrace discharge structure at a higher elevation to address silting. The Ambuklao dam will also need some repair works in relation to erosion and damage to the embankment, repairs to gates, and general maintenance. Rehabilitation is to take two years and is targeted for completion in July 2010.Binga was built downstream of Ambuklao in 1960, and is also of rockfill construction, maximum height of 107 m, a crest length of 400 m, and a 4.26 km2 reservoir area. Binga will be upgraded with the construction of a new intake and the replacement of each generation unit per year during dry season when all units are not needed. Plant rehabilitation will include construction of a new intake similar to Ambuklao as well as installation of new electrical and mechanical equipment. The Binga dam will need some repair works in relation to damage to the embankment, a deficiency in spillway capacity, and other maintenance and repairs. Completion of the refurbishment plan targeted for the first half of 2013.As Ambuklao is upstream to Binga the Ambuklao reservoir supplements the reservoir for Binga as well allowing for the operation of the two power plants in cascade. This will be important in the future, as sedimentation progress is expected to lead to a run of river situation at Binga by 2027. SNAPB does not plan on desilting the reservoir and will instead operate the plant in a manner that will regularly remove silt from the areas immediately in front of the intake.Being a refurbishment of an existing renewable energy project, it is well aligned with IFC’s Climate Change Strategy. Electricity from Ambuklao and Binga is sold to the Luzon grid, one of the three major island grids in the Philippines. Luzon grid is predominantly thermal-based, which accounts for 70% of electricity generated, while hydro and geothermal account for the remaining 20% and 10% respectively. The refurbished project will generate an estimated 755 GWh for 2010 onwards, and annually avoid greenhouse gas emissions equivalent to an estimated 550,000 tons of CO2 from displaced thermal generation.