Renewable energy sources: Their global potential for the first-half of the 21st century at a global level: An integrated approach

The risk of human-induced climate change and the volatility of world oil markets make non-fossil fuel options important. This paper investigates the potential for wind, solar-PV and biomass (WSB) to deliver energy. The focus is on land opportunities and constraints and on production costs as a function of resource availability and depletion and of innovation dynamics. The context is provided by the IPCC SRES scenarios as simulated with the IMAGE 2.2 model. We explicitly consider several sources of uncertainty, aspects of the food vs. energy trade-off and the effects of interaction between the three options through their claims on land. We show that ‘potential production’ concepts are strongly dependent on the chosen land-use scenario—and should therefore be used with an indication of the underlying assumptions. Our results indicate a potential for liquid biofuels in the order of 75–300 EJ year−1 and for electricity from WSB options at production costs below 10 ¢ kWh−1 of 200–300 PWh year−1. Theoretically, future electricity demand can be amply met from WSB sources in most regions by 2050 below 10 ¢ kWh−1, but major uncertainties are the degree to which land is actually available and the rate and extent at which specific investment costs can be reduced. In some regions, competition for land among the three WSB options may significantly reduce the total potential as estimated from simple addition—which is another source of uncertainty.