In a new report, researchers from the German National Academy of Sciences Leopoldina say that crops should only be used to generate a small amount of energy, reports ScienceInsider. The panel of experts argues that there are a number of drawbacks to biofuels, including competition with food crops, adverse effects on ecosystems through nutrient depletion and subsequent fertilizer use, and emissions. "Rather, Germany should concentrate on other renewable energy sources such as solar heat, photovoltaics, and wind energy, whose area demand, [greenhouse gas] emissions, or other environmental impacts are lower than those of bioenergy," the report says. "Energy conservation and energy efficiency improvements should have priority."