Transmission planning in a market-based environment

The challenges for transmission planning in an increasingly market-based environment for the supply and delivery of electricity are many. In many parts of the world, the industry has evolved over the past decade from one dominated by fully regulated vertically integrated utilities to a structure which includes many new players and where generation has been largely divested from transmission. In many parts of the United States, new institutions have been introduced-Independent Transmission Operators ("ISOs") and Regional Transmission Operators ("RTOs") -- which have a critical role to play in the operation and planning of the transmission system and wholesale electric markets. While wholesale generation is largely priced at market-based rates, the role and structure of an "open access" transmission system in a market-based environment continues to be a source of great debate. The result is that the role of the transmission planner has become increasingly more complex.