Chapter 18 science
Terms in this set (71)
Energy from sources that are constantly being formed
Like solar energy, what sources does renewable energy include?
Power of moving water
Do all sources of energy affect the environment?
What does a space station and plant have in common?
Both powered by the sun
What does the sun do?
It radiates energy from nuclear fusion reactions in its core
Does all of the Suns energy reach the earth?
No, only a small fraction
What is an example of direct solar energy?
When the sun shines on a window and heats a room
Passive solar heating
Uses the Suns energy to heat something DIRECTLY
In a solar heating system, what is the liquid pumped through?
Active solar heating
Energy from the sun can be gathered by collectors and used to heat water or heat a building
What do solar collectors do?
Capture the Suns energy
What is about 8% of the the energy in the U.S. used for?
What are solar cells also called?
What do solar cells do?
Converts the Suns energy into electricity
Do solar cells have moving parts?
No, they run on non polluting power from the sun
Do solar cells produce a small or large electric current?
What are some benefits of solar cells?
Does energy from the sun warm the earths surface evenly or unevenly?
What does wind power convert the movement of wind into?
Large arrays of wind turbines
Do wind turbines take up little space or a lot of space?
What is a problem with wind energy?
Transporting electricity from rural areas where it's generated to urban centers where it's needed
Plant material, manure and other organic matter that's used as an energy source
What are some sources of energy In developing countries?
(renewable biomass energy sources)
What is nearly half of the wood cut in the world used for?
Fuel for heating and cooking
If trees are cut down faster than they can grow, what are some consequences of this?
What can methane be used for
Generate heat or electricity
Blend of gasoline and ethanol
Does gasohol produce less or more energy than fossil fuels?
Less air pollution
Energy produced from moving water
What % of hydroelectric energy accounts for the world electricity
List 6 countries that lead in hydroelectric energy:
What is the dam used In a hydroelectric power plant used for?
Hold back a reservoir of water
What does the water in a reservoir do?
It's released to a turbine
Which generates electricity
Are hydroelectric dams expensive to build?
Are hydroelectric dams expensive to OPERATE?
No, they are inexpensice
Do hydroelectric dams last longer than fossil fuel powered plants?
What are some benefits of dams (5)
Disadvantages of hydroelectric energy;
Electricity produced in a small stream without having to build a big dam
What is less expensive?
Micro hydropower or hydroelectric dam projects?
Energy from heat in The earths crust
What does the UNITED STATES produce the most?
What is the world largest geothermal power plant?
Is geothermal energy considered a renewable source or nonrenewable source
Geothermal heat punp
Used stable underground temperatures to warm and cool homes
In the winter is the ground warmer or Cooler than the air?
Describes energy that doesn't come from fossil fuels and that is still in development
What must be done for an alternative energy source to become a viable option for the future?
Must be proven cost effective
Environmental effects of using energy source must be acceptable
What does a tidal power plant work likev
In a tidal power plant, what happens as the tide rises
The water gets recalled behind the dam
In a tidal power plant, what happens during low tide
The water rushed through the dam and spins a turning which generates electricity
Some cons of tidal energy?
Expensive to build
Hard to maintain
Ocean thermal energy conservation (OTEC)
Use of temperature differences in ocean water to produce electricity
List the steps of OTEC
Warm surface water boiled in vacuum chamber
Produces steam that drives a turbine to generate electricity
Cold front ocean water condenses steam
Steam turns to water that can be used again
What are OTEC plants inefficient?
1/3 of the electricity the plant produces is used to pump cold water up from the deep ocean
What is the most abundant element in the universe
What can hydrogen be used for?
Burned as fuel
Does hydrogen contain carbon?
Does hydrogen release pollutants associated with burning fossil fuels and biomass?
What does hydrogen combine with in the atmosphere?
Oxygen which produces water vapor
One difficulty or hydrogen use
Takes a lot of energy to produce
Device that produces electricity chemically by combining hydrogen fuel with oxygen from the air
What can fuel cells by filed by?
Anything containing a lot of hydrogen
(Natural gas, alcohol, gas)
What are 2 ways to reduce energy use?
Energy efficiency increaee
Percentage of energy put into a system that does useful work
Hybrid cars energy efficiency features:
Convert energy of braking into electricity and are stored in batteries
Engine shut off to save fuel
Aerodynamic and use less energy to speed up
Production of 2 useful firms of energy from the same fuel source
Process of saving energy by reducing energy use and waste
How much does the average house spend of energy bills each year?
Conservation around the house examples:
Avoid blocking vents
Close doors in unused rooms
Turn off lights when room is not used