ALTERNATIVE ENERGY SOURCESWorld-wide, with the exception of coal, which has known reserves that will last a couple of centuries, the known reserves of oil are expected to be exhausted in your lifetime...
Clearly, alternative energy sources are needed for the future
U.S. Energy Consumption
The four primary consumers of energy in the U.S. in 2007 were
Industrial 32%
Transportation 28%
Residential 22%
Commercial 18%
93% of the energy generated and used in the U.S. are from nonrenewable resources
We will look at:
Solar energy
Geothermal power
Hydropower
Tidal Power
Ocean thermal energy conversion
Wind energy
Biomass
Solar Energy
The Sun is free (nobody owns or controls it)
In principle, the amount of solar energy that reaches the Earth’s surface could provide for all human energy needs forever
The distribution of solar energy over the continental U.S. in watts per square meter
The desert regions of the southwest U.S. receive the most sunlight
Clean Solar Energy
Solar energy is clean energy
It produces no hazardous solid, liquid or gas wastes
It does not create water or air pollution
The two areas in which solar energy can make the greatest contribution are in space heating and in the generation of electricity
These are uses that account for two-thirds of U.S. energy consumption
Solar Heating
The simplest approach to solar heating is passive-solar heating
The building design should allow the maximum amount of sunlight to stream in through south and west windows during the cooler months
This heats the house and materials inside
Trees can be positioned to shade the house in summer
Wide eaves can shade windows in summer, but allow winter sunlight to enter
Drapes and shutters can insulate window areas in winter
It has been estimated that 40 to 90% of most homes’ heating requirements could be supplied by passive-solar heating systems
100% solar homes have been built, but such homes usually cost many tens of thousands of dollars more to build
Retrofitting older homes to be solar efficient can be too costly
Over insulation can aggravate indoor pollution
Solar Electricity
Direct production of electricity using sunlight is accomplished using photovoltaic cells, also called solar cells
They have no moving parts and are “clean” energy
They are used to power the space station and to provide electricity in remote areas on Earth
A major limitation is cost, which greatly exceeds the cost of producing electricity using fossil fuels or nuclear power
The best solar cells are only 20% efficient and only provide 50 watts of electricity per square meter of cell size
A 100 watt light bulb would require 2 square meters of solar cells
And a 100-megawatt power plant would require 2 square kilometers (0.78 square miles) of solar cells
This represents a major use of land and resource, which would use far more steel and concrete than a fossil fuel power plant
Storing Solar Electricity
In a solar energy home, extra electricity is stored in batteries for later use
This work well for one house
Unfortunately, no wholly practical technology has been developed to store large amounts of electricity, despite advances in batteries
Some possible schemes for storing the energy of solar generated electricity include breaking up water into oxygen and hydrogen to burn later as fuels
Also pumping water to an elevated reservoir for later use as hydroelectric power generation
Currently, solar energy provide less that 0.5% of the U.S. power needs, but even with existing technology, it could provide up to 15%
Geothermal Power
Magma rising from the mantles brings unusually hot material near the surface
Heat from the magma, in turn, heats any groundwater
This is the basis for generating geothermal energy
The steam and/or hot water is used to create electricity or for heating
Geothermal Power Plants
Worldwide, there are now about 40 geothermal power plants, especially in Japan, Mexico and the Philippines
Note that most geothermal power plants are built along plate tectonic boundaries
Clearly, alternative energy sources are needed for the future
U.S. Energy Consumption
The four primary consumers of energy in the U.S. in 2007 were
Industrial 32%
Transportation 28%
Residential 22%
Commercial 18%
93% of the energy generated and used in the U.S. are from nonrenewable resources
We will look at:
Solar energy
Geothermal power
Hydropower
Tidal Power
Ocean thermal energy conversion
Wind energy
Biomass
Solar Energy
The Sun is free (nobody owns or controls it)
In principle, the amount of solar energy that reaches the Earth’s surface could provide for all human energy needs forever
The distribution of solar energy over the continental U.S. in watts per square meter
The desert regions of the southwest U.S. receive the most sunlight
Clean Solar Energy
Solar energy is clean energy
It produces no hazardous solid, liquid or gas wastes
It does not create water or air pollution
The two areas in which solar energy can make the greatest contribution are in space heating and in the generation of electricity
These are uses that account for two-thirds of U.S. energy consumption
Solar Heating
The simplest approach to solar heating is passive-solar heating
The building design should allow the maximum amount of sunlight to stream in through south and west windows during the cooler months
This heats the house and materials inside
Trees can be positioned to shade the house in summer
Wide eaves can shade windows in summer, but allow winter sunlight to enter
Drapes and shutters can insulate window areas in winter
It has been estimated that 40 to 90% of most homes’ heating requirements could be supplied by passive-solar heating systems
100% solar homes have been built, but such homes usually cost many tens of thousands of dollars more to build
Retrofitting older homes to be solar efficient can be too costly
Over insulation can aggravate indoor pollution
Solar Electricity
Direct production of electricity using sunlight is accomplished using photovoltaic cells, also called solar cells
They have no moving parts and are “clean” energy
They are used to power the space station and to provide electricity in remote areas on Earth
A major limitation is cost, which greatly exceeds the cost of producing electricity using fossil fuels or nuclear power
The best solar cells are only 20% efficient and only provide 50 watts of electricity per square meter of cell size
A 100 watt light bulb would require 2 square meters of solar cells
And a 100-megawatt power plant would require 2 square kilometers (0.78 square miles) of solar cells
This represents a major use of land and resource, which would use far more steel and concrete than a fossil fuel power plant
Storing Solar Electricity
In a solar energy home, extra electricity is stored in batteries for later use
This work well for one house
Unfortunately, no wholly practical technology has been developed to store large amounts of electricity, despite advances in batteries
Some possible schemes for storing the energy of solar generated electricity include breaking up water into oxygen and hydrogen to burn later as fuels
Also pumping water to an elevated reservoir for later use as hydroelectric power generation
Currently, solar energy provide less that 0.5% of the U.S. power needs, but even with existing technology, it could provide up to 15%
Geothermal Power
Magma rising from the mantles brings unusually hot material near the surface
Heat from the magma, in turn, heats any groundwater
This is the basis for generating geothermal energy
The steam and/or hot water is used to create electricity or for heating
Geothermal Power Plants
Worldwide, there are now about 40 geothermal power plants, especially in Japan, Mexico and the Philippines
Note that most geothermal power plants are built along plate tectonic boundaries
1)How do scientists define energy? The ability to do work.
2)Explain the law of conservation of energy. Give examples of energy transformations. Energy is neither created nor destroyed.
3)What is energy efficiency? Amount of useful energy obtained from any type of system.
4)What does it mean for energy to be nonrenewable? Renewable? Nonrenewable means it will run out. Renewable means it will form again.
5)According to the “U.S. Energy Consumption by Energy Source, 2012”, what percentage of energy that we use is renewable? What percent is nonrenewable? 10% renewable 90 % nonrenewable
Renewable Energy Sources
6)What are the 6 forms of renewable energy resources? Hydroelectric, biomass, solar, wind, geothermal, biofuels.
8)Solar energy is converted into what energy? renewable
9)Give two examples of how solar energy is used. For electricity.
10)What do solar cells do? Converts light into energy.
11)What do solar power plants do? Supply electricity to a power grid.
12)What are the 2 main disadvantages to solar energy? costly, spacious
13)Explain how solar energy is beneficial for the environment. It’s beneficial because the only thing you need to make electricity is the sun.
15)What did American colonists use windmills for? Used windmills to grind wheat and corn, to pump water, and to cut wood at sawmills.
16)What do wind machines produce? Energy
17)Describe a wind power plant. A wind power plant produces a lot of energy
18)Describe the negative effects of wind machines. Its costs a lot of money.
20)What is geothermal energy? The thermal energy generated and is stored in the earth.
21)Geothermal energy is generated in the ground.
22)Where is geothermal energy found? Geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface.
23)Name 2 ways people have used direct geothermal energy? Hot springs for bathing and cooking food.
24)Describe how has Iceland used geothermal energy? They used it for electricity.
26)Name 5 things that are biomass materials. Corn stalk, bushes, grass, leaves, sawdust.
27)What is the most common biomass material? corn
28)84% of wood energy is used where? It is used as fire wood.
29)How can biomass energy be negative to the environment? Produces smog.
31)What 3 states hold over one-half of the total U.S. hydroelectric capacity for electricity is _Washington, California, Oregon.
32)Most dams in the United States were not built to provide electricity, but for prevent flooding and provide rural environment.
34)Compare wind turbines and wave turbines. They both produce electricity
35)Not only could the ocean provide us with tidal energy, but hydro energy.
36)What is Ocean Thermal Energy Conversion? Uses the temperature difference between cooler deep and warmer shallow or surface seawaters to run a heat engine and produces electricity.
37)Since the ocean expands almost two-thirds of the Earth, it makes sense to use that open ocean to provide us with energy. What are the two forms of energy have scientists considered placing over the open ocean? Hydroelectric and wind energy.
38)What are the 4 areas in which energy is used? Land, water, underground, air
40)What is the most used type of energy in the home? The lights.
2)Explain the law of conservation of energy. Give examples of energy transformations. Energy is neither created nor destroyed.
3)What is energy efficiency? Amount of useful energy obtained from any type of system.
4)What does it mean for energy to be nonrenewable? Renewable? Nonrenewable means it will run out. Renewable means it will form again.
5)According to the “U.S. Energy Consumption by Energy Source, 2012”, what percentage of energy that we use is renewable? What percent is nonrenewable? 10% renewable 90 % nonrenewable
Renewable Energy Sources
6)What are the 6 forms of renewable energy resources? Hydroelectric, biomass, solar, wind, geothermal, biofuels.
- “Solar”
8)Solar energy is converted into what energy? renewable
9)Give two examples of how solar energy is used. For electricity.
10)What do solar cells do? Converts light into energy.
11)What do solar power plants do? Supply electricity to a power grid.
12)What are the 2 main disadvantages to solar energy? costly, spacious
13)Explain how solar energy is beneficial for the environment. It’s beneficial because the only thing you need to make electricity is the sun.
- “Wind.”
15)What did American colonists use windmills for? Used windmills to grind wheat and corn, to pump water, and to cut wood at sawmills.
16)What do wind machines produce? Energy
17)Describe a wind power plant. A wind power plant produces a lot of energy
18)Describe the negative effects of wind machines. Its costs a lot of money.
- “Geothermal”
20)What is geothermal energy? The thermal energy generated and is stored in the earth.
21)Geothermal energy is generated in the ground.
22)Where is geothermal energy found? Geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface.
23)Name 2 ways people have used direct geothermal energy? Hot springs for bathing and cooking food.
24)Describe how has Iceland used geothermal energy? They used it for electricity.
- “Biomass”
26)Name 5 things that are biomass materials. Corn stalk, bushes, grass, leaves, sawdust.
27)What is the most common biomass material? corn
28)84% of wood energy is used where? It is used as fire wood.
29)How can biomass energy be negative to the environment? Produces smog.
- “Hydroelectric.”
31)What 3 states hold over one-half of the total U.S. hydroelectric capacity for electricity is _Washington, California, Oregon.
32)Most dams in the United States were not built to provide electricity, but for prevent flooding and provide rural environment.
- “Ocean”
34)Compare wind turbines and wave turbines. They both produce electricity
35)Not only could the ocean provide us with tidal energy, but hydro energy.
36)What is Ocean Thermal Energy Conversion? Uses the temperature difference between cooler deep and warmer shallow or surface seawaters to run a heat engine and produces electricity.
37)Since the ocean expands almost two-thirds of the Earth, it makes sense to use that open ocean to provide us with energy. What are the two forms of energy have scientists considered placing over the open ocean? Hydroelectric and wind energy.
- “Use of Energy.”
38)What are the 4 areas in which energy is used? Land, water, underground, air
- “Residential- homes.”
40)What is the most used type of energy in the home? The lights.