In October 2008, the State of Hawaii and the Hawaiian Electric Companies entered into the Hawaii Clean Energy Agreement to move Hawaii off of its dependence on imported fossil fuels for electricity and transportation. The U.S. Department of Energy contracted R.W. Beck in 2008 to evaluate interconnection of the transmission systems of the islands of Lanai, Molokai and Maui with Oahu. Phase I of this independent review included an initial evaluation of the technical configuration and capital costs of establishing an undersea cable system and examining impacts to the existing electric transmission systems as a result of interconnecting the islands. To move forward from the foundational work of the R.W. Beck report [1] and in support of the Hawaiian Clean Energy Agreement, the Department of Energy through the National Renewable Energy Laboratory contracted Electranix Corporation to study the undersea cable system necessary to transmit 400 MW of wind energy from the islands of Lanai and/or Molokai to Oahu (Stage 1) and the future installation of a 200-MW capacity cable system to interconnect the island of Maui (Stage 2).

The study effort included a technical feasibility assessment and budgetary cost estimate of the undersea transmission interconnect options. Inputs from the suppliers of undersea power cables and direct current (DC) converter station has been provided. Six DC cable options and one AC cable option were selected from 18 alternative configurations were developed by building on the R.W. Beck study [1]. Only one of the selected options included undersea cable transmission between Lanai and Molokai whereas all the alternatives from this previous study included undersea cable transmission between the two islands. The economic justification for undersea cable transmission between Lanai and Molokai could not easily be established, so the feed to Oahu from these islands was radial only...(read more...)