Fluctuations in individual renewable-energy supplies are largely reduced by distributing the renewable energy over a wide-area transmission network. Therefore, a new analysis algorithm for determining the amount of renewable energy in a wide-area transmission network was developed in this study. Accounting for the power interchange in the transmission network and the energy storage in electric heat pumps and heat storage tanks, the objective function plans the arrangement of the electric power sources that maximizes the economic efficiency of the system. The developed algorithm was applied to Hokkaido, Japan. The areas and capacities of the introduced renewable energies, and the amount of electric power interchanged through the transmission line, were determined. The installed capacity and economic efficiency of the backup power supply and energy storage equipment (heat storage) were also investigated. In this area, the introductory rate of renewable energy was 39.5% of the total electricity production. Moreover, the cost of a distributed power-supply network was 9.99 x 10(10) USD. The proposed system is equivalent to 1.88 years of Hokkaido's energy consumption. (C) 2017 Elsevier Ltd. All rights reserved.