A review of the experience of IEA countries after the oil crises in the 1970s, which initiated a surge of investments in renewables research and development. While use of renewables has grown rapidly, they still account for only a small portion of the IEA energy mix. This work examines policies and measures that have been introduced in IEA countries to increase the cost effective deployment of renewables, reviews the objectives behind these policies, and evaluates the results.