15.3 energy resources. review what is energy, kinetic, potential? what is energy conversion?...

15.3 Energy Resources

Review

• What is energy, kinetic, potential?

• What is energy conversion?

• What’s the law of conservation of energy?

Nonrenewable Energy Resources

• Nonrenewable Energy Resources- exist in limited quantities and, once used, cannot be replaced except over the course of millions of years– These resources are being used much faster

than they can be replaced…– Include: oil, natural gas, coal and uranium

• Fossil Fuels- were formed underground from the remains of once-living organisms– Ex: oil, natural gas, and coal– Currently, fossil fuels account for the great

majority of the world’s energy use – Their use creates pollution

Nonrenewable Energy Resources

Renewable Energy Resources

• Renewable energy resources- resources that can be replaced in a relatively short period of time.– Most renewable resources originate directly or

indirectly from the sun– Include: hydroelectric, solar, geothermal and

wind energy

1) Hydroelectric Energy

• Hydroelectric Energy- energy obtained from flowing water– Some hydroelectric power plants simple

depend upon the natural flow of water in a river – Most rely on dams build across rivers

• A dam blocks the flow of water, storing potential energy that is converted into kinetic when the water is released

– Low cost to produce, lack of pollution

2) Solar Energy

• Solar Energy- sunlight that is converted into usable energy– Passive solar designs use sunlight to heat a building

without using machinery• For example. Sunlight passing through the windows of a

house may be absorbed by thick walls and then radiate thermal energy

– In an active solar system, sunlight heats flat collection plates through which water flows

• The heated water may be used directly for the buildings hot water needs, or it may be used to heat the house

**Solar Energy is non-polluting but for areas where cloudy days are frequent, solar energy is less practical

3) Geothermal Energy

• Geothermal Energy- thermal energy beneath the Earth’s surface

– The geothermal powerplant pumps water into the ground, where it turns into steam. The steam isthen used to drive electric generators. – Non polluting, but it not widely available

Conserving Energy Resources

• Energy Conservation- finding ways to use less energy or use energy more efficiently– Making appliances, cars, and even light bulbs

more energy efficient is a way or reducing energy use while still enjoying its benefits

– Energy-efficient purchases often cost more initially, but can save money in fuel costs over time

• Page 466– Problems 1-5