Catalyst 1/8 Distinguish between the 1st Law of Thermodynamics and the 2nd Law of Thermodynamics and give an example of each law in action Use the 2nd Law of Thermodynamics to explain why energy cannot be recycled

IN THIS CHAPTER, WE WANT TO UNDERSTAND: WHAT ENERGY IS THE SOURCES OF ENERGY THE USES OF ENERGY EFFECTIVE ENERGY PLANNING Ch. 17 – Energy Basics

Energy Crisis in Ancient Rome and Greece Greeks used wood as primary source of heat energy Fuel shortages: forests were depleted Started building homes facing the south  Low winter sun entered the houses, providing heat  High summer sun was partially blocked, cooling the houses Romans used glass windows  Developed greenhouses to raise food in winter

Energy Crisis Today Fossil fuels, which take millions of years to form, may run out in the next few hundred years  The decisions we make today will affect generations Trade offs:  Use of fossil fuels, primarily oil, has improved sanitation, medicine, and agriculture  Burning fossil fuels leads to pollution and environmental degradation Uncertainty about cost and supply  We depend on other countries for energy sources

Energy Basics Energy is the ability to do work 1 st law of thermodynamics: energy can neither be created nor destroyed  We can convert it or transform it, but total energy remains the same 2 nd law of thermodynamics: energy moves from high quality to low quality when used

Kinetic vs. Potential Energy

Energy Efficiency Two fundamental types of energy efficiencies are derived from the first and second laws of thermodynamics:  the first-law efficiency and the second-law efficiency. First-law efficiency deals with the amount of energy without any consideration of the quality or availability of the energy.

Energy Efficiency Second-law efficiency refers to how well matched the energy end use is with the quality of the energy source.  Low values indicate where improvements in energy technology and planning may save significant amounts of high-quality energy.

Energy Sources Fossil Fuels (Non-renewable)  Coal, petroleum (oil), natural gas Alternative Energy (Renewable)  Geothermal, solar, wind, hydropower, nuclear Fossil fuel resources are finite  Will only be used for approx. 500 years of all of human history (since the Industrial Revolution) 90% of energy in US comes from fossil fuels

Energy Use in US The US is 5% of the world’s population, but uses 25% of the world’s energy  Are we using energy efficiently and fairly? Residential and Commercial (39%) Industrial (34%) Transportation (27%) We lose energy in the form of waste heat during production of electricity and transportation

Energy Conservation and Efficiency Conservation of energy  Simply getting by with less demand for energy. Increased energy efficiency  Involves designing equipment to yield more energy output from a given amount of input energy (first-law efficiency)  Better matches between energy source and end use (second- law efficiency).

Cogeneration  Processes designed to capture and use waste heat rather than release it as a thermal pollution.  Using that waste heat, can increase the overall efficiency of a typical power plant from 33% to as much as 75%  Could provided an estimated 10% of the power capacity of the US

Building Design A spectrum of possibilities exists for increasing energy efficiency and conservation in residential buildings.  Design and construct homes that minimize the energy consumption  Design buildings to take advantage of passive solar potential  For older homes:insulation, caulking, weather stripping, installation of window coverings, storm windows, and regular maintenance.

Industrial Energy Industrial production of goods continues to grow significantly.  U.S. industry consumes about one-third of the energy produced.  More industries are using co-generation and more energy- efficient machinery.

Catalyst 1/12 Work in a group of 2-4 people to design a poster, advertisement, or slogan that encourages people to change their values or choices to live more energy efficiently Requirements:  Colorful, attractive, engaging  Encourages energy efficiency  Creative and unique

Values, Choices, and Energy Conservation Ways of modifying behavior to conserve energy include the following:  Ride a bike, walk, or take a bus or train to work.  Using carpools to travel to and from work or school  Purchasing a hybrid car (gasoline-electric)  Turning off lights when leaving rooms  Taking shorter showers (conserves hot water)  Putting on a sweater and turning down the thermostat

Values, Choices, and Energy Conservation  Using energy-efficient compact florescent lightbulbs  Purchasing energy-efficient appliances  Sealing drafts in buildings with weather stripping and caulk  Better insulating your home  Washing clothes in cold water whenever possible  Purchasing local foods to reduce energy in transport  Using powerstrips and turning them off when not in use

Automobile design Early 1970s, the average US automobile got 14 mpg. By 1996, the average was 28 mpg for highway driving. Today, some hybrid (gasoline-electric) vehicles exceeds 90 mpg on the highway and 60 mpg in the city. Improvement has several causes:  Increased efficiency and resulting conservation of fuel  Cars that are smaller, w/ engines constructed of lighter materials  Combination of a fuel-burning engine with an electric motor

Energy Policy U.S. energy policy during the past half-century has not moved us closer to energy self-sufficiency.  We import more oil than ever.  In the late 1990s, the US spent $2 billion per year on research and development for energy.  By comparison, $45 billion per year went to R and D for the military.

Energy Policy Act of 2005 Some of the provisions are as follows.  1. Promotes conventional energy sources  2. Promotes nuclear power  3. Encourages alternative energy  4. Promotes conservation measures  5. Promotes research  6. Provides for energy infrastructure

Hard Path vs. Soft Path Hard path involves finding greater amounts of fossil fuels and building larger power plants. The second road of energy policy is called the soft path  It involves energy alternatives that emphasize:  energy quality  are renewable  are flexible  are environmentally more benign than those of the hard path

Energy for Tomorrow To stabilize the climate in terms of global warming, use of energy from fossil fuels would need to be cut by about 50%.  Reductions in energy use need not be associated w/ lower quality of life.

Energy for Tomorrow What is needed is increased conservation and more efficient use of energy:  More energy-efficient land-use planning that maximizes the accessibility of services and minimizes the need for transportation.  Agricultural practices and personal choices that emphasize  1. Eating more locally grown foods  2. Eating more vegetables, beans, and grains.  Industrial guidelines for factories that promote energy conservation and minimize production of waste.

Integrated, Sustainable Energy Management The global pattern of ever-increasing energy consumption led by the US cannot be sustained w/o a new energy paradigm  Includes changes in human values rather than a breakthrough in technology.  Choosing to own fuel-efficient automobiles and living in more energy-efficient homes are consistent with a sustainable energy system.