In Des Moines on Tuesday, a representative of the nonprofit Natural Resources Defense Council said low-income households benefit the most from cutting energy costs through energy efficiency and renewable energy. Katharine McCormick, Midwest advocate for the group, noted that the average American household spends 2.9 percent of income on energy costs. By comparison, low-income families spend 8.3 percent of income on energy. NRDC’s report,“Bridging the Clean Energy Divide,” shows how a transition to cleaner power and reduced emissions can lead to to healthier communities, greater savings and a stronger economy.