This paper analyzes the optimal options for supplying electricity to national economies from both domestic and distant energy resources using high voltage lines to transmit the substantial renewable energy resources of Africa. To meet the growing demand, Africa will need to provide 5.2 GW of new generation per year through 2025. This figure represents an increase of 65% from the 2010 level and will assist in connecting more than 11 million new customers per year through the development of a transmission network. The total discounted system cost is approximately 8% of the continent's GDP. Approximately two-thirds of the discounted system cost is associated with new generation, and the remaining one-third is associated with the development of the transmission network. From 2010 to 2025, trade expansion reduces the total system cost by 21% relative to the business as usual (BAU). (C) 2013 Elsevier Ltd. All rights reserved.