Energy Efficiency and Conservation

Abstract

Previous chapters in this book focus on the production of energy from different sources and how we might increase the supply to meet the anticipated growth in demand. In this chapter we focus on options to manage the energy demand. There are many ways—other than complete avoidance of the use of goods or services that demand energy—by which we can “save” energy; actually, we are not saving but reducing the growth in the demand of energy. It is often convenient to think of savings arising from two categories: energy efficiency and energy conservation. Energy efficiency reduces the energy necessary to perform a desired task, and energy conservation includes all actions that avoid unnecessary use of energy. To use the automobile as an example, development of techniques that reduce the fuel needed to go from one place to another is an example of improved energy efficiency. Substituting the automobile with a more efficient mode of transportation or the avoidance of the activity entirely would be examples of energy conservation. Thoughtful use of both conservation and efficiency will be necessary if we are to achieve substantial reductions in our future energy use as individuals, nations, or the world as a whole. As discussed in chapter 4, the global energy use projected for 2050 under three scenarios with three differing growth rates ranges from a high of 9.4 CMO/yr to a low of 3.9 CMO/yr. Our recent energy use of approximately 3 CMO/yr (since 2000) is on a growth curve that follows the trajectory of the high-consumption scenario. Improvements in energy efficiency have of course been made steadily over the past century and will likely continue in the future. Much of that improvement has already been taken into account in arriving at the projections for future growth. The 2.6% annual growth in energy consumption has taken place notwithstanding steady improvements in efficiency. To bring the projected 2050 consumption down from more than 9 CMO, we will need savings that would not happen without a rededicated effort.