Limitations on the renewability of renewable energy resources

The primary supposition about renewable forms of energy is that use of such resources will not result in depletion or exhaustion. While it is true that natural energy flows such assun and wind are not directly subject to degradation by use, there may still be indirect limitations on renewability. The exploitation of natural energy flows may require that systems of nonrenewable “support” resources be used to capture, store, and convert natural energy into useful forms. Poor resource management practices that degrade the support resources may therefore, in effect, endanger renewability. Biomass is an illustrative case of a renewable energy resource with nonrenewable support components. The soil and water management practices of American agriculture, a large-scale biomass production system, are resulting in serious degradation and depletion of these vital system elements. This degradation represents a threat to the future of biomass food and energy supplies.