We would be remiss if we don't include energy efficiency in our discussions over renewable energy. Energy efficiency is not a source of renewable energy, but instead facilitates energy sustainability by releasing renewable energy generation for other uses. As we shall see, increasing energy efficiency is an important element to achieving long-term energy sustainability. First, we must understand that energy is of little value by itself. Energy is valuable only because it provides useful energy services such as light, heat, cold food, electric motors, electronics, communication, and so forth. We desire and consume electricity and energy in order to provide energy services not because we simply want to possess energy somehow. Energy services are of value to individuals and to society as a whole. Energy efficiency does not increase our store of energy, but instead represents the combined technical improvements that provide useful energy services while using less energy. In other words, getting more services for less energy. The chart to the right shows four broad categories of energy services: industrial, transportation, residential, and commercial services. Another way of thinking about energy efficiency is that it reduces the need for energy generation. So saving a kilowatt hour of electricity is equivalent to producing a kilowatt hour by other means. These savings are sometimes called megawatts. For example, replacing a 100 watt incandescent light bulb with a 15 watt LED bulb provides the same energy service, in this case light, but it also produces 85 megawatts unused power that doesn't need to be generated. Reducing demand with energy efficiency reduces required generating capacity while producing the same energy surfaces like using less capacity at lower costs and with lower greenhouse gas emissions. Energy efficiency figures prominently in most plants for meeting 2050 Greenhouse Gas Reduction goals. These plants understand that both renewable energy and energy efficiency offer roughly the same amount of mitigation potential, but only when working in synergy. This first graph shows the timeline of energy efficiency reduction goals to 2050 by efficiency sector. The second graph breaks down these broad categories or goals into subsectors. There's too much detail here to quickly digest, which illustrate one of the great challenges of energy efficiency. Energy efficiency is not one program or one technology, it's a myriad of much smaller programs and thousands of technologies, large and small. Because of this, it's hard to articulate what to do. The answer to what to do will vary widely by sector, subsector, facility, and industry, making it difficult to speak with any generality about what to do for energy efficiency. As an example of this challenge, this illustration from McKinsey and Company, a large consulting firm, shows a variety of energy efficiency ideas in residences, commerce, and industry. Column widths represent the energy efficiency potential and column heights represent the relative costs through the efficiency effort. This graph has far too much detail to quickly grasp, but here are three examples. The first is industrial energy management systems which are relatively inexpensive but could significantly reduce energy consumption. The second is duck ceiling and basement installation in residences. The third example is energy improvement of commercial lighting. Understanding how to implement each of these broad efficiency improvements would take considerable time, study, and effort. There are several dozen other programs itemized in this diagram, each of which you'd require similar time, study, and effort. This is the challenge of energy efficiency efforts. How to bring energy efficiency to the four of renewable energy efforts when it is highly fragmented, complex, and time-consuming. The pay off is large, but so is the effort. The advantages of energy efficiency are many. We use less energy, deliver the same energy services. Energy efficiency usually pays for itself over the long-term. Energy efficiency reduces greenhouse gas emissions as well as other pollutants. Energy efficiency creates more comfortable living and working environments and promotes energy resilience, self-sufficiency, and reduces energy risks. But the challenges of energy efficiency are also many. Energy efficiency projects often have large upfront expenses in incremental annual savings, resulting in long payback periods. It may be difficult to measure and monetize efficiency savings. Efficiency efforts often instill a multitude of many small improvements with few homeruns to feature. In some cases, the monetary cost of efficiency may exceed savings, even if energy sustainability and resiliency are markedly improved. Energy efficiency efforts are often technically complex, requiring upfront expertise in ongoing operations and maintenance. These challenges and others make energy efficiency efforts daunting. This brief video barely touches on the complex topic of energy efficiency. But it's important for us to remember that along with renewable energy technologies, energy efficiency is an equally important component necessary to achieve long-term energy sustainability goals.
