Renewable energy futures: Targets, scenarios, and pathways

Abstract

Scenarios for the future of renewable energy through 2050 are reviewed to explore how much renewable energy is considered possible or desirable and to inform policymaking. Existing policy targets for 2010 and 2020 are also reviewed for comparison. Common indicators are shares of primary energy, electricity, heat, and transport fuels from renewables. Global, Europe-wide, and country-specific scenarios show 10% to 50% shares of primary energy from renewables by 2050. By 2020, many targets and scenarios show 20% to 35% share of electricity from renewables, increasing to the range 50% to 80% by 2050 under the highest scenarios. Carbon-constrained scenarios for stabilization of emissions or atmospheric concentration depict trade-offs between renewables, nuclear power, and carbon capture and storage (CCS) from coal, most with high energy efficiency. Scenario outcomes differ depending on degree of future policy action, fuel prices, carbon prices, technology cost reductions, and aggregate energy demand, with resource constraints mainly for biomass and biofuels. Copyright © 2007 by Annual Reviews. All rights reserved.