A simple evaluation method for annual CO ₂ emissions reduced by distribution loss minimization

Global warming caused by carbon dioxide (CO ₂) and other greenhouse gases is one of the serious environmental issues. Carbon dioxide is the biggest contributor to global warming. Many efforts to reduce emissions of CO ₂ are carrying out in various fields. In electrical power system field, various approaches to reduce CO ₂ emissions have been performed such as loss reduction, utilization of renewable energy, recycling of resources and so on. Especially, distribution loss minimization is effective to reduce CO ₂ emissions because reduction of distribution loss leads to save the energy. For example, the largest distribution system in Japan consists of about 19,000 feeders. Much CO ₂ emissions can be reduced by minimizing distribution loss of the largest distribution system. However, CO ₂ emissions reduced by distribution loss minimization for the largest Japanese distribution system have not been estimated so far. In this paper, the authors try to calculate annual CO ₂ emissions reduced by distribution loss minimization for a distribution system model based on partial actual data, which is composed by 19,000 distribution feeders, 95,358 sectionalizing switches and 73,849 load sections. In the trial calculation, reduced CO ₂ emissions are estimated by sequentially proceeding four procedures: (1) classification of distribution system model into several load areas, (2) determination of loss minimum configuration in each load area, (3) calculation of reduced annual distribution loss for each area, and (4) calculation of reduced annual CO ₂ emissions. As the result of the trial calculation, reduced annual CO ₂ emissions of 40 × 10 ⁶ kg/year is estimated for the Japanese largest scaled 19,000 feeders distribution model.