A Graph Is Worth a Thousand Gigawatt-Hours: How California Came to Lead the United States in Energy Efficiency (Innovations Case Narrative: The California Effect)

transportation, refrigeration, and industrial processes. Our continued dependence on combustion produces carbon dioxide, contributing to the increasing concentrations of greenhouse gases (GHGs) in the earth’s atmosphere. Although energy efficiency alone will not likely be enough to reverse this trend, currently it is by far the fastest, cleanest, and cheapest energy resource available. This article will discuss how my colleagues and I have promoted energy efficiency over the last 40 years. Our efforts have involved thousands of people from many different areas of expertise. The work has proceeded in several areas: • Investigating the science and engineering of energy end-use • Assessing the potential and theoretical opportunities for energy efficiency • Developing analytic and economic models to quantify opportunities • Researching and developing new equipment and processes to bring these opportunities to fruition