The future promotion of the conductor upsizing requires the development of guidelines for determining the optimum size from the viewpoints of both cost effectiveness and environment, as well as the international standardization there of IBC. To be more specific, it is necessary to create an “Environmental Current Table” (tentative name) instead of the conventional “Allowable Current Table.” So, we carry out development and research on theoretical formulae for creating the new table, as follows: (1) Find the life cycle cost. (2) Find the range of a current that minimizes the life cycle cost, and (3) Derive the environmental current. (4) Fix x (equivalent load factor for one day) and y (yearly operating days).
Most past research on this subject was implemented before 2005, when people started concerning themselves about global warming. Accordingly, this research on size optimization focusing on the environment (C02 emissions) is the world's first.