Effective Measures for CO2 Reduction Harnessing the Potential Water Energy Present in the Water Service Industry

Sapporo Waterworks Bureau's (SWB's) measures for CO2 reduction started in 1982 with a hydropower project at the Moiwa Water Purification Plant (MWPP) (cap. 155,000 m3/day). Operation of the generator was temporarily discontinued in 2001 for full-scale reconstruction of the water purification plant (WPP); after the completion of the reconstruction, the power generation equipment was renewed, and the operation resumed as a joint project with a private company in 2007. Power generation is on-site since the hydropower generator within the MWPP area provides energy consumed at the MWPP and the adjoining Waterworks Museum. This power generation is expected to create an energy saving effect equivalent to 1,500 tons of CO2 and over 10 million yen of annual net benefit. In order to increase the usage rate of low-cost, clean energy like hydropower at the WPP, SWB has made a series of adjustments to the operating methods of the plant. Then, as a result, the generation covers 97% of the energy used on-site at present. Furthermore, SWB is considering introducing other hydropower facilities of this kind that harness water transmission energy from the Shiraikawa WPP (cap. 650,000 m3/day) to the major distribution reservoirs.