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 depletedStarted 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 degradationUncertainty about cost and supply

We depend on other countries for energy sources

Energy Basics

Energy is the ability to do work 1st law of thermodynamics: energy can

neither be created nor destroyed We can convert it or transform it, but total

energy remains the same2nd 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

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.