Macrogrids and Supergrids: Wide Area Transmission to Improve Electrification and Variable Renewable Energy Use

Studies have shown that wide area high-voltage dc (HVdc) electric power grids will be needed for the future. In North America, these are known as “macrogrids” and in Europe, “supergrids,” which are sometimes referred to as “hypergrids.” There are obstacles in the way to achieving these wide area grids, however. What are these obstacles, and how can they be overcome? Such obstacles include passing through multiple jurisdictions and obtaining permitting. The NIMBY challenge is one such issue. Of course, a wide area transmission grid will pass through different countries and states, adding to the permitting challenge. The processes that are being applied include the use of rights-of-way of existing railroads or highways. Underwater locations may include those beneath lakes and rivers as well as those undersea. In the United States, the right-of-way of a rail line is being used to traverse several states for 2,100-MW, ±525-kV HVdc cables. Roadside rights-of-way are also under active consideration for HVdc cables for the macrogrid.