Distributed solar electricity generation across large geographic areas, Part I: A method to optimize site selection, generation and storage

Perhaps the greatest obstacle to large-scale solar energy generation is the intermittent nature of solar energy and the associated costly storage. This paper presents a method to optimize combinations of selected worldwide regions in different time zones with the surprising capability of providing sufficient electricity generation to overcome intermittency or reduce it to such an extent that substantially less storage and generation capacity are needed. The recent sharp drop in the cost of photovoltaic (PV) generation capability accompanied by worldwide increased investment in PV plants suggests a new economic base for cooperative efforts to sequentially combine day time insolation. The approach presented here optimizes two aspects, first, the selection of sites across large geographic areas, and second, the size and relative proportion of generation and storage capacity at each site. Our approach converts 20 years of daily insolation data by NASA Solar Sizer to hourly scale. The hourly data are used to assess and compare supranational distributed solar networks in different parts of the globe that have recently been proposed, and to subsequently optimize their generation capacity and storage. We show that linking regions in different time zones and on the two hemispheres can fully eliminate intermittency without the need for fuel and renewable energy other than solar. (C) 2012 Elsevier Ltd. All rights reserved.