Name __________________________________________ Date ________________ Hour __________
Chapter 18 Renewable Energy
Key Terms
1. Renewable energy – energy from sources that are constantly being formed
2. Passive solar heating – uses the sun’s energy to heat something directly
3. Active solar heating – the gathering of solar energy by collectors that are used to heat water or heat a building
4. Biomass fuel – plant material, manure, or any other organic matter that is used as an energy source
5. Hydroelectric energy – electrical energy produced by the flow of water
6. Geothermal energy – the energy produced by heat within Earth
7. Alternative energy – energy that does not come from fossil fuels and that is still in development
8. Ocean thermal energy conversion (OTEC)- the use of temperature differences in ocean water to produce
electricity
9. Fuel cell – a device that produces electricity chemically by combining hydrogen fuel with oxygen from the air
10. Energy efficiency – the percentage of energy put into a system that does useful work
11. Energy conservation – the process of saving energy by reducing energy use and waste
Section 1 Review Questions
1. List six forms of renewable energy, and compare the advantages and disadvantages of each.
Solar cells are non-polluting and have no moving parts, but they are inefficient and expensive. Passive solar
energy requires no fuels, but efficiency depends on location. Wind energy is inexpensive, but transmitting
electricity from remote sites is difficult. Biomass produces less pollution than fossil fuels, but it can produce
environmental problems if used in a nonrenewable manner. Hydroelectricity facilities are inexpensive to
operate and produce no air pollution, but they can have adverse effects on the environment and the
surrounding population. Geothermal plants are less polluting than fossil-fuel plants and require no fuels, but
hydrothermal water deposits can be exhausted and facilities can be expensive to build.
2.
Describe the differences between passive solar heating, active solar heating, and photovoltaic energy.
Passive solar heating uses the sun’s energy directly by incorporating features into a building’s construction.
Active solar heating stores the sun’s energy and uses it indirectly to heat water or a building. Photovoltaic
energy uses the sun’s energy indirectly to generate electricity.
3.
Describe how hydroelectric energy, geothermal energy, and geothermal heat pumps work.
To produce hydroelectric energy, flowing water turns a turbine, which generates electricity. Geothermal energy
is generated when heated water or steam is pumped up from inside Earth to power a turbine that generates
electricity. Geothermal heat pumps circulate fluid in a pipe underground and back to the surface to heat or cool
a house.
4.
Explain whether all renewable energy sources have their origin in energy from the sun.
All of the sources have their origin in solar energy except geothermal. Solar is ‘solar’. Wind is caused by the
uneven heating of the earth’s surface by the sun. The water cycle is powered by the sun. Biomass is produced
by photosynthesis which is powered by the sun.
5.
Which renewable energy source would be best suited to your region? Write at least 3 sentences explaining
why.
NOT solar – it is too cloudy. NOT tidal – our tides aren’t big enough; NOT wind – it is not windy enough.
Probably biomass would be the best suited for our region. We have lots of plant material. There are lots of
paper mills and we could use the leftover wood scraps as a biomass fuel source. . .
6. Identify a modern trend in hydroelectric power and in wind energy.
Micro-hydropower is increasing. Electricity is being produced in a small stream without having to build a big
dam. The turbine may even flow tint he water not blocking the river at all. Also wind power is increasing.
7.
What is the difference in biomass fuel use between developed and developing countries?
Developing countries use wood-fuels and dung as energy sources. Developed countries use methane or alcohol
from wastes.
Section 2 Review Questions
1. Describe three alternative energy technologies, and identify two ways that hydrogen could be used as a fuel
source in the future.
Tidal power uses the energy of the tides to power a turbine that generates electricity. OTEC produces electricity
by driving a turbine with steam that has been heated by warm surface water. The steam is turned back to liquid
again by cooling with cold water from the deep ocean. Hydrogen can be used directly by burning it as fuel, or it
can be stored in a fuel cell and then combined with oxygen to produce electricity.
2.
List as many ways as you can for individuals and communities to conserve energy.
Turn off unused lights and appliances (TV, Computer) unplug things when not in use, clean refrigerator coils, airdry clothes, wrap your hot water heater, adjust thermostat (78 in summer and 68 in winter). Replace old
windows, insulation, weather strip around doors and windows, water saving shower heads and toilets
3.
Describe the difference between energy conservation and energy efficiency.
Energy conservation involves reducing the amount of energy we use. Energy efficiency involves getting more
useful work out of the energy that we use.
4.
What factors influence a person’s choice to conserve energy?
Financial situation, personal values about the need to conserve, availability of conservation choices
5.
Read the description of hydrogen fuel cells and explain why hydrolysis is the opposite of the reaction that
occurs in a hydrogen fuel cell.
During hydrolysis water molecules are split into hydrogen and oxygen using electricity. In a fuel cell, hydrogen
and oxygen are combined to produce electricity and water is produced as a byproduct.