Energy Flows and Nutrients Cycle Solar energy CO2 given off as waste by animals and used by plants 100% energy Chemical energy H2O + P + N from soil 90% energy lost to heat 10% energy passed down Producers turn sunlight into food O2 given off as waste and used by consumers 90% energy lost to heat 1% energy left C, N, H passed on to consumers Primary consumers turn plant energy into animal energy 90% energy lost to heat .1% energy left Secondary consumers turn stored animal energy into animal energy Decomposers return nutrients to soil N, H2O, P are returned to the soil