science ~ chapter 12 energy and material resources
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Science ~ chapter 12 energy and material resources. Miss Nelson. Section 1. Renewable Sources of Energy. Anticipatory set. What other sources can you name besides coal, oil, and natural gas?. standards. S 6.6.a- - PowerPoint PPT PresentationTRANSCRIPT
Miss Nelson
SCIENCE ~ CHAPTER 12
ENERGY AND MATERIAL
RESOURCES
Renewable Sources of Energy
SECTION 1
What other sources can you name besides coal, oil, and natural gas?
ANTICIPATORY SET
S 6.6.a-Students know the utility of energy sources is determined by factors that are involved in converting these sources to useful forms and the consequences of the conversion process
S 6.6.b-Students know the different natural energy and material resources, including air, soil, rocks, minerals, petroleum, fresh water, wildlife, and forests; and know how to classify them as renewable or nonrenewable
STANDARDS
What forms of energy does the sun provide?
What are some renewable sources of energy?
THE BIG IDEA
Solar energy – energy from the sun
Hydroelectric power – electricity produced using the energy of flowing water
Biomass fuel – fuel made from living things
KEY TERMS
Gasohol – a mixture of gasoline and alcohol
Geothermal energy – heat from Earth’s interior
Tide – the regular rise and fall of Earth’s waters along its shores
KEY TERMS
Read Renewable Sources of Energy on page 485 of your textbook.
RENEWABLE SOURCES OF ENERGY
The sun constantly gives off energy in the forms of light and heat
HARNESSING THE SUN’S ENERGY
Solar energy is the source (either directly or indirectly) of most other renewable energy resources
Solar energy does not cause pollution, and will not run out for billions of years
Disadvantages It is only available when the sun is shining Sunlight is very spread out – to obtain a large amount
of power, it is necessary to collect solar energy from a large area
HARNESSING THE SUN’S ENERGY
One way to capture the sun’s energy involves using giant mirrors
In a solar power plant, rows of mirrors use the sun’s rays to heat a tank of water
The water boils, creating steam, which can be used to generate electricity
SOLAR POWER PLANTS
Solar energy can be converted directly into electricity in a solar cell
Has a negative and positive terminal (like a battery)
When light hits the cell, and electric current is produced
Solar cells power some calculators, lights, and other small devices
SOLAR CELLS
Can be used to heat buildings
Converts sunlight into thermal energyDistributed with pumps or fans
Just like a car heating up on a hot day
PASSIVE SOLAR HEATING
Captures the sun’s energy and then uses pumps and fans to distribute the heat
Light strikes the dark metal surface of a solar collector
Converted to thermal energy
Water is pumped through pipes in the solar collector to absorb the thermal energy
The heated water flows to a storage tank and fans distribute the heat throughout the building
ACTIVE SOLAR HEATING
Read Harnessing the Sun’s Energy on page 486 of your textbook
HARNESSING THE SUN’S ENERGY
Other renewable sources of energy include:WaterWinBiomass fuelsGeothermal energyThe tides
HYDROELECTRIC POWER
Solar energy is the indirect source of water power (heat from the sun drives the water cycle)
Hydroelectric power is electricity produced by flowing water
A dam across a river controls the flow, which turns turbines creating power
Hydroelectric power is the most widely used source of renewable energy
HYDROELECTRIC POWER
Read Hydroelectric Power on page 488 of your textbook
HYDROELECTRIC POWER
Is also an indirect form of solar energyThe sun heats the Earth’s surface unevenly. As a result, different areas of the atmosphere have different temperatures and air pressures, which causes wind as air moves from one area to another
Wind can be used to turn a turbine and generate electricity
WIND POWER
The fastest growing energy resource
Drawbacks:Many areas do not have sufficiently strong winds to support wind farms
Wind farms require a lot of landWind often blows strongest in scenic areas, where people object to seeing wind turbines
WIND POWER
Read Wind Power on pages 488-489 of your textbook
WIND POWER
Wood was probably the first fuel ever used for heat and light
Wood belongs to a group of fuels called biomass fuels Are made from material that was once part of a living thing
Other biomass fuels include leaves, food wastes, and manure
Biomass fuels can also be converted into other fuels Some crops can be used to make alcohol; adding this to
gasoline forms gasohol, and can be used in fuel for cars Methane gas can be used to heat buildings
BIOMASS FUELS
Are renewable resources
…but it takes time for new trees to replace those that have been cut down
Are not widely used in the United States
BIOMASS FUELS
Read Biomass Fuels on page 489 of your textbook
BIOMASS FUELS
Below Earth’s surface are pockets of very hot liquid rock called magma
In some places it is very close to the surface
The intense heat from Earth’s interior that warms the magma is called geothermal energy
In certain places (Iceland and New Zealand) magma heats underground water to a boiling point Hot water and steam can be valuable sources of
energy
TAPPING EARTH’S ENERGY
Geothermal energy is an unlimited source of cheap energy
Disadvantages:Only a few places where magma comes close to Earth’s surface
Other places, very deep wells would be needed to tap this energy
TAPPING EARTH’S ENERGY
Read Tapping Earth’s Energy on page 490 of your textbook
TAPPING EARTH’S ENERGY
The tides are the regular rise and fall of Earth’s waters along its shores Caused by the gravitational pull of the moon and sun
Tidal power plants have been built to take advantage of this regular motion
Although it is a clean, renewable source of energy, it has several limitations There are only a few places in the world where the
tides are high and low enough to build plants A dam across a bay would block boats and fish from
passing through
TIDAL ENERGY
Read Tidal Energy on page 491 of your textbook
TIDAL ENERGY
What two forms of energy does the sun supply?
What are two reasons that solar energy has not replaced energy from fossil fuels?
CHECK FOR UNDERSTANDING
What two forms of energy does the sun supply?The two forms of energy the sun produces are heat and light energy.
What are two reasons that solar energy has not replaced energy from fossil fuels?Two reasons that solar energy has not replaced energy from fossil fuels are that solar energy is only available when the sun is shining, and that it must be collected from a very large area.
CHECK FOR UNDERSTANDING
List five renewable energy sources other than solar energy.
Which of these forms are actually indirect forms of solar energy? Explain.
GUIDED PRACTICE
List five renewable energy sources other than solar energy.Fiver non-solar renewable energy sources are wind, water, biomass, geothermal, and tidal energy.
Which of these forms are actually indirect forms of solar energy? Explain.Wind and water energy are actually indirect forms of solar energy because water power depends on the water cycle, which is driven by the sun, and wind energy depends on uneven heating of the Earth by the sun.
GUIDED PRACTICE
Complete Energy 12-2 Independent Practice
INDEPENDENT PRACTICE