CO2. A new factor to be considered on the design of electrical distribution grids

Traditionally, the design of the primary undergrounded circuits for electrical distribution has been based on technical exploitation criteria, as load capacity, reliability, service quality, losses, and economical concerns as installation cost, being so achieved a compromise which minimizes the investment cost on the basis of optimizing the cable section. This procedure maintains its validity from the technical point of view but, nowadays, a new environmental and economical concern should be taken in account in order to determinate the optimum section of an undergrounded cable. This new factor is just the emission of greenhouse effect gasses, as CO2, consequence of the primary source of energy used in the electrical energy production. The ecological impact of these emissions is being increasing its relevance as increases the social conscience on environmental concerns, in particular, since the signature of the Kyoto Agreement. In this work, we present a designing method which considers the part of generation of energy necessary to cover the losses in the undergrounded distribution lines, and includes the cost of the CO2 emissions in the computation of the optimum section of the cable. It is concluded that by increasing the section in such a way, a relevant amount of the Joule losses can be saved in comparison to that produced by the cross section obtained by a classical procedure. The investment excess could be paid back quickly by avoiding administrative fines and by selling the corresponding emission rights.