High voltage DC for resource development

Natural sources of energy are often remotely located and transportation to the point of utilization becomes a problem. Although energy in the form of fuel for thermal plants may be physically transported, it may be converted to electrical energy at the source, as is usual in the case of hydraulic energy. Electrical energy may be transmitted by conventional alternating current transmission systems, subject to certain limitations. When the distances are great or when water crossings are involved, the limitations of AC systems make DC transmission an attractive alternative.