Diesel-based electricity production is relatively expensive in small autonomous power systems which rely on fuel imports. In such systems, the introduction of renewable energy technologies can effectively reduce overall production costs, through fuel savings. However, the penetration of intermittent renewable energy sources, such as wind, into diesel-based grids is limited because of their disruptive effect on power quality and reliability. In the case,of wind turbines, a high penetration requires changes in system design and management, such as grid reinforcements. The additional costs can reduce overall system performance and ultimately limit the exploitation of wind energy resources. This manuscript briefly outlines the reasons that restrict wind penetration in diesel-based electricity systems and reviews estimates and examples of autonomous and interconnected power systems. (c) 2004 Elsevier Ltd. All rights reserved.