gies that are widely available in the market and well proven. Embedded in the scenario is the assumption that energy efficiency will improve over time in response to market forces as well as to codes and standards. Under these conditions, residential electricity use is projected to increase by an average of 1.4 percent per year, and commercial electricity use by 1.9 percent per year, over the period from 2006 to 2030. The potential for energy savings that is computed here is above and beyond that embodied in the baseline used for the analysis.
Figures 4.3 through 4.6 are the supply curves developed for this study. They illustrate the potential for energy efficiency improvements over the period 2010–2030 in the residential and commercial sectors for electricity and natural gas. The x-axis shows the total reduction in 2030 energy consumption, while the y-axis shows the CCE in fuel-specific units. Each step on the curve represents the total savings for a given end-use for all the cost-effective efficiency measures analyzed to that point. These plots are referred to as supply curves because they indicate how much energy savings is available for a given cost, with the CCE calculated as