Chapter 18 Renewable EnergySection 1 Renewable Energy Today

Renewable Energy• Renewable energy is ________________________________________________________________________________________. • Types of renewable energy includes:

• _________________________________ energy• _________________________________ energy• the power of __________________________________________________________• __________________________________________

• Remember, all sources of energy, including renewable sources, ______________________________________.

Solar Energy-Power from the Sun• Nearly all renewable energy comes ___________________________________________________________________

from the _____________________.• Direct solar energy is used every day, like when _____________________________________________________

______________________________________.• Solar energy can also be used indirectly to ___________________________________________________________.

Passive Solar Heating• Passive solar heating is the ____________________________________________________________________________.• In the Northern

Hemisphere, ______________________ facing windows receive the most solar energy.

• Therefore, passive solar buildings have

_________________________________________________________________.• An average household could ________________________________________________________________ by using any

of the passive solar features shown here.

Active Solar Heating• Active solar heating is the ___________________________________________________________________________________• More than _______________________________ homes in the United States use active solar energy to heat

water.• _______________________________________, usually mounted on a roof, capture the sun’s energy.

Active Solar Heating

Name____________________________________Date ______________________ Per __________

• A liquid _______________________________________________ as it flows through solar collectors.• The hot liquid is then _______________________________________________________, which heats water for the

building.• About ___________ of the energy

used in the United States is used to ____________________; therefore, active solar technology could save a lot of ___________________.

Photovoltaic Cells• Photovoltaic cells are

__________________________________

____________________________________________________________________• Solar cells have ________________ ___________________________ and they run on

_________________________________ power from the sun.• However, they produce a very small __________________________________________. Meeting the electricity

needs of a small city would require covering hundreds of acres with solar panels.** (update)

Sunlight falls on a ___________________________________________, causing it to release ___________________________. The electrons flow through a _________________________ that is complete when another semiconductor in the solar cell ______________________ _________________________ and passes them on to the ________________________ __________________________________________...

• Solar cells require extended periods of sunshine to produce electricity. This energy _______________________________ ___________________________, which supplies electricity when ______ ____________________________________________________

• Currently, solar cells provide energy for more than ____ ________________________________________________ in

developing countries, where energy consumption is minimal and electricity __________________________________________________________________________________________.

Wind Power• Energy from the sun warms the Earth’s surface unevenly, which causes _______________________________

in the atmosphere.• We experience the movement of these air masses ____________________________.• Wind power, which _____________________________________________________________________________________, is

the fastest growing energy source in the world.• _______________________________________________ are used to capture the energy from the wind.• Large arrays of wind turbines are called _______________________________________. Large wind farms

supply electricity to ____________________________________ of homes.

• In ________________________________________________________, small wind farms with 20 or fewer turbines are also becoming common.

• Because wind turbines ____________________________________________________________, some farmers can _______________________________________________________________________________________________and still use the land for other purposes.

• The cost of wind power has been ____________________________ as wind turbines have become _______________________ .

An Underdeveloped Resource• Scientists estimate that the

windiest spots on Earth could generate _____________________ ________________________________ the energy used worldwide.

• In the future, the electricity may be used on the wind farm __________________________________________________________________________.

• Today, all of the large energy companies are ________________________________ to use more wind power.

Biomass-Power from Living Things• Biomass fuel consists of ____________________________________________________________________________________

______________________________________________________________________________________________________________• Fossil fuels can be thought of as _____________________________________________________, although they are

nonrenewable.• Renewable biomass fuels, such as ______________________________________, are major sources of energy in

______________________________________________.• More than half of all wood cut in the world is used as ___________________________________________________.• Although materials like wood are a _____________________________________________, if trees are cut down

faster than they grow, the resulting ________________________________________________________________________ can be severe.

• In addition, harmful _________________________________________ may result from burning wood and dung.

Methane• When _____________________________________________________________________________________, one byproduct is

methane gas.• Methane can be __________________________________________________________________.• In China, more than 6 million households use ________________________________________________ to ferment

manure and produce gas for heating and cooking.• Some ________________________________in the United States generate electricity by using the methane

from the ______________________________________________________________________.

Alcohol• _______________________________________ can also be derived from biomass.• For example, ___________________________________, an alcohol, can be made by fermenting fruit or

agricultural waste. In the United States, ___________________________________________________________________.

• Cars and trucks can run on _______________________________________________________, a blend of gasoline and ethanol. Gasohol produces __________________________________________________________ than fossil fuels.

• Some states require the use of _____________________________ in vehicles as a way to reduce air pollution.

Hydroelectricity-Power from Moving Water• Hydroelectric energy is ___________________________________________________________________________________.• Hydroelectric energy accounts for __________________ of the world’s electricity.• Large hydroelectric power plants have a ___________________ that is _______________________________________

_________________________________________________________________________________________________________________• The water in the reservoir is released to __________________________________________________________________,

which __________________________________________________________

The Benefits of Hydroelectric Energy• Hydroelectric

dams are ____________________ ___________________, but relatively ____________________ ___________________.

• Unlike fossil fuel plants, hydroelectric dams do not release ___________________________________________ that cause acid precipitation.

• Hydroelectric dams also tend to _____________________________________________________________ than fossil fuel-powered plants.

• Dams also provide other benefits such as _______________________________________________________________ ___________________________________________________________________________

Disadvantages of Hydroelectric Energy• A dam _____________________________________________________________________________, which can have far-

reaching consequences.• A reservoir ________________________________________________________ above the dam. Water flow below the

dam is ___________________________________ which disrupts ecosystems downstream.• For example, many salmon fisheries of the northwestern United States have been destroyed by

_____________________________________________________________________________________________________________• When the land behind a dam is flooded, people are often _________________________________. If a dam

__________________________________, people living in areas below the dam can be killed.• _________________________________________________________ build up behind the dam instead of _______________

_________________________________________________________________________________________ making farmland below the dam less productive.

• Recent research has also shown that the decay of plant matter trapped in reservoirs can release large amounts of ___________________________________________-sometimes more than a fossil-fuel powered plant.

Modern Trends• While in developing countries the construction of _______________________________ continues, in the

United States, the era of large dam construction is probably over.

• One modern trend is _____________________________________________________, which is electricity produced in a small stream without having to build a big dam. The turbine may even __________________________ ___________________________________________________________________________________________

• Micro-hydropower is __________________________________________ than large hydroelectric dam projects, and it permits energy to be generated from _______________________________________________________________ areas.

Geothermal Energy-Power from the Earth• In some areas, deposits of ________________________ in the

Earth’s crust are _______________________________ _______________________________________.

• ______________________________________ is the energy produced by heat within the Earth.

• ____________________________________________ is the world’s largest producer of geothermal energy.

• Although geothermal energy is considered a ________________________________ resource, the water that is used must be ___________________________________________ ___________________________________________________________

• Geothermal power plants generate electricity using the following steps• ______________________________________________________

______________________________________________________• ______________________________________________________

______________________________________________________• ______________________________________________________

______________________________________________________• The leftover liquid, water, is returned to Earth’s crust

because it can be reheated by geothermal energy and ___________________________________.

Geothermal Heat Pumps: Energy for Homes• More than 600,000 homes in the United States are heated and cooled using __________________________

______________________________.

• A geothermal heat pump uses

____________________________________________________ ______________________________________ because the temperature of the ground is __________________ ______________________________________ year-round.

• A heat pump is simply a _____________ ________________________________________________that circulates a _______________________________________ underground.

• In the summer, the ______________________ _________________________ than air and the fluid __________________ the home.

• In the winter, the ________________________ __________ ______________________ than air, and the fluid _______________________ the home.

Chapter 18 Renewable EnergySection 2 Alternative Energy & Conservation

Alternative Energy• To achieve a future where energy use is ________________________________, we must make the most of

the energy sources we already have and ______________________________________________ of energy.• Alternative energy describes energy that ________________________________________________________________

and that is still in development.• For an alternative energy source to become a viable option for the future, the source must be

________________________________________________________________________________.• Also, the ________________________________________________________________________ of using the energy

source must be acceptable.

Tidal Power

• A _____________________

_______________________________ works much like a hydroelectric dam.• As the tide rises, _______________________________ _______________________________

_______________________________ then _________________________ ______________________________.• At low tide, _________ ______________________________ _____________________________, spinning a

__________________ _______________________________ electricity.• Although tidal energy is ____________________ & _________________________, it will not become a major

___________________________________ in the future.• The cost of ______________________________________________________________________ tidal power plants is

high, and there are few ______________________________________________________________________.

Ocean Thermal Energy Conservation• In the tropics, the temperature difference between the

______________________________of the ocean and the ____________________________ocean waters can be as much as 24ºC (____________ºF).

• Ocean thermal energy conservation (OTEC) is the ________________________________________________________________________ ________________________________________________________________________

• An OTEC plant produces energy using the following steps• _______________________________________________________________

_______________________________________________________________• This produces ___________________ that drives a

_________________________________________ electricity.•________________________________________________________________________________________________________.• The steam turns into water that can be _________________________________.

• _____________________________ & ______________________ have experimented with OTEC power, but so far, no project has been able to generate __________________________________________________ electricity.

• OTEC plants are inefficient because about one-third of the electricity the plant produces is used to ______________________________________________________________________________________.

• The ________________________________________________________________ of pumping large amounts of cold water to the surface are also ________________________________________.

Hydrogen-A Future Fuel Source?• ______________________, the most abundant element in the universe, can be _______________________________.• Hydrogen does not contain _______________________, so it does not _________________________________________

associated with burning fossil fuels and biomass.• When hydrogen is burned in the atmosphere, it _________________________________________________________

________________________, a harmless byproduct, and small amounts of ___________________________oxides.• Hydrogen gas (H2) can be produced by _______________________________________________ to split molecules

of ________________________________• Hydrogen fuel can be made from _______________________________ that contains a lot of

___________________.• In the future, we may also be able to ____________________________________________ to produce _____________

_______________________________________________________

The Challenge of Hydrogen Fuel• One difficulty of using hydrogen as a fuel today is that hydrogen ______________________________________

____________________________________________.• If this energy came from burning fossil fuels, ____________________________________________________________

_____________________________________________________________________________________________________• One alternative is to use electricity ___________________________________________________________________ to

split water molecules to produce hydrogen.• Hydrogen could then be stored in ________________________________________________________________ and

transported in gas _________________________________________________________. • Or hydrogen might not be stored at all-it might be used as it is produced, in __________________________.

Fuel Cells• A fuel cell is a

___________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________

• When hydrogen and oxygen are combined, ___________________ ______________________ is produced and _________________________ is the only byproduct.

• Fuel cells can be fueled by anything that contains plenty of hydrogen, including ____________________________________________________ ________________________________________________________________________________________________________________

Energy Efficiency• There are two main ways to reduce energy use:

• _____________________________________________________________• _____________________________________________________________

• Energy efficiency is the __________________________________________ ______________________________________________________________________.

• Energy efficiency can be determined by this equation: ______________________________________________________________________

• Most of our devices are __________________________________________. More than _________________ of all commercial energy used in the United States is ______________________________.

• Increasing efficiency may involve ____________________________ or _____________________________________________________________________

Efficient Transportation• Developing efficient _______________________ to power vehicles

and increasing the use of ___________________________________________________________ would help increase ____________________________________________________________ of American life.

• The ___________________________________________________________________________ that power most vehicles do so inefficiently and produce air pollution.

• In the next 50 years, the design of these engines may _____________________________________________ to meet the need for more ______________________________________________________________________.

Hybrid Cars• Hybrid cars are examples of ___________________________________________________________________.• Hybrid cars use small, efficient _________ ___________________ ____________ most of the time, but they also

use ___________________ ___________________ when extra power is needed, such as while accelerating.

• Hybrid cars _____________ ___________________ __________________ conventional vehicles, they cost __________ to

____________________________, and they produce ____________________________ ___________________________________.

• Hybrid cars feature many ________________________________ technologies. • They convert some energy of ________________________________________________________ and store

this energy in the _________________________.• The gasoline engine is sometimes _____________________________________________________, such as

when the car is stopped at a red light.• They are ____________________________________ in design and need less energy to accelerate.

Cogeneration• Cogeneration is the ________________________________________________________________________________________.• For example, the ________________________________________________ from an industrial furnace can power a

_________________________________________ that produces electricity.• Small cogeneration systems have been used for years to supply ________________________________________

to multiple buildings at specific sites.

Energy Conservation• Energy conservation is the _______________________________________________________________________________.• This can occur in many ways, including ______________________________________________________________ and

_________________________________________________________________________• Between 1975 and 1985, ____________________________________made more __________________________________

in the United States than all ____________________________________________________________________________ did.

Cities and Towns Saving Energy• The town of Osage, Iowa, numbers 3,600 people. • This town saved more than ______________________________________ in energy because they _______________

____________________________________________________________________• In addition to saving energy, the town has greatly improved its ________________________________________

through energy conservation.• Businesses have ___________________________________________________________ to take advantage of __________

_______________________________________________ Unemployment rates have also ____________________________

Conservation Around the Home• The average

household in the U.S. spends _____________ _____________ on energy bills each year.

• Unfortunately, much of the energy from homes is _________________ _________________ ____________________________________________________________________ windows, doors, walls, and the roof.

• There are dozens of ways to __________________________________________________________ around the home.

Conservation in Daily Life• There are many ________________________________________________________________ that can help save energy.• Using __________________of any resource usually translates into ___________________________________________.