Global and Local Pollutant Emissions Displacement due to Power Transmission Expansion

Power transmission expansion planning has been frequently solved through economical and reliability perspectives, without focusing on the environmental implications of the incorporation of transmission lines. In this paper, the authors study the environmental effects on global and local pollutant emissions derived from the incorporation of some specific new transmission circuits in both new and existing corridors and their interrelationship with power system costs and system reliability variations. For this purpose, the authors develop a methodology that quantifies the indirect impact on pollutant emissions due to variations in power plants' generation when adding a line circuit to a hydrothermal power system. The methodology also allows the analysis of the effect of N-1 security criterion over the pollutant emissions displacement, as well as the effect of changes in demand, the hydrological scenarios, and the failure cost. The authors illustrate the methodology using a 203-node simplified version of the main Chilean network. Results suggest that pollutant emissions show an important relation with the network's structure and the system's reliability level. Furthermore, it is shown that there may be some unpredicted distributed environmental implications of adding a line circuit into a hydrothermal system.