Most of us first became conscious of our energy use during the oil embargoes of 1973 and 1978. We were confronted with the conflict between comfort, cost, and even having enough fuel to live a normal life, perhaps best remembered by gasoline rationing for our cars. We also have new environmental agendas that will shape our energy choices for the coming decades. Air quality, leaking underground tanks, and tightening building codes will reshape the economic choices for energy use in homes in the future. This energy flow diagram illustrates how energy is used in the United States.