Globally, the total annual primary energy consumption in 2005 is estimated to be 500 quadrillion (10
The U.S. consumes 105 quadrillion Btu, distributed in segments shown in Figure 1.1. About 40% of the total primary energy consumed is used in generating electricity. Nearly 70% of the energy used in our homes and offices is in the form of electricity. The worldwide demand of 15 trillion kWh in 2005 is projected to reach 19 trillion kWh in 2015. This constitutes a worldwide average annual growth of 2.6%. The growth rate in developing countries is projected to be approximately 5%, almost twice the world average.