Chapter 16.1 16-1 Why Is Energy Efficiency an Important Energy Resource? A. Energy saved through efficiency reduces the need for the production of energy from another source. Energy efficiency is a measure of the useful energy produced compared to the energy that is converted to low-quality heat energy. About 84% of all commercial energy used in the U.S. is wasted. About 41% is wasted because of the degradation of energy quality imposed by the second law of thermodynamics. About 43% of the energy used in the United States is unnecessarily wasted by such things as motor vehicles, furnaces, and living and working in leaky, poorly designed buildings. Since the 1980s, the U.S. has reduced the amount of energy used per person, but unnecessary energy waste still costs the U.S. about $570,000 per minute. B. Much energy is wasted because of widespread reliance on incandescent light bulbs, internal combustion engines, nuclear power plants, and coal-fired power plants. CASE STUDY: Building a smarter and more energy-efficient electrical grid. A smart grid is an energy efficient, high-voltage power grid with very efficient transmission lines that is responsive to changes in supply and demand. China is investing heavily in the technology and may become the leader. Energy experts place high priority of converting outdated grids to smart grids. C. Industry accounts for 30% of global energy consumption. D. Ways to save money and energy in industry include: 1. Cogeneration using a combined heat and power system 2. Replacing energy wasting electric motors 3. Recycling materials 4. Replacing low-efficiency incandescent lighting E. Transportation accounts for 28% of energy consumption in the United States. 1. Between 1973 and 1985, fuel efficiency increased because of government-mandated corporate average fuel economy standards. Since 1985 fuel economy has gone down. 2. Ways to save energy in transportation include offering incentives to purchase more efficient vehicles, shifting to electric rail systems, and encouraging bicycle use. F. More energy efficient vehicles are now being produced and more are planned. 1. These include hybrids, plug-in hybrids, energy efficient diesels, fuel cell technology, and vehicles made of ultra-light and ultra-strong composite materials. SCIENCE FOCUS: The search for better batteries. Lithium-ion batteries, commonly found in cell phones and laptops, are the most promising for electric vehicles. However, there are drawbacks, such as possible risk of fire, and cost. Modern research is bringing about promising alternatives. G. We can save energy in buildings by getting heat from the sun, super insulating them, and using plant-covered green roofs. We can save energy in existing buildings by insulating them, plugging leaks, and using energy-efficient heating and cooling systems, appliances, and lighting. H. There are three reasons renewable energy is not more widespread: 1. Since 1950, tax breaks, subsidies, and research funding have been much lower for renewable energy than for fossil fuels. 2. Subsidies and tax breaks are virtually guaranteed for fossil fuels and nuclear power, but must be renewed by Congress every few years for renewable energy. 3. The prices we pay for fossil fuels do not include their detrimental effects on the environment.