Ch. 18 Renewable Energy
Benefits of solar power
-Solar technologies use no fuel -Solar devices require very little maintenance -The production reduces dependence on power plants
Benefits of passive solar energy
1. No air pollutants 2. reduces heating bill/ free resource 3. abundant resource
What three purposes are dams designed to serve?
1. They bring water to areas that don't have it 2. controls flooding 3. hydroelectric power is generate
What are the benefits of renewable energy sources?
1. They're unlikely to run out 2. They decrease air pollution and greenhouse gas emissions 3. The World will be less dependent on energy from foreign nations
Cons of active solar energy
1. When no sunlight shines (such as at night,) no energy is produced 2. costly upfront 3. Many regions aren't sunny enough to use this energy
Benefits of tidal energy
1. clean source 2. reduces greenhouse gas emissions
Costs of wind energy
1. constantly scares off birds and wildlife 2. creates noise pollution 3. Eyesore 4. High upfront cost 5. Fast winds aren't near population centers 6. Winds are unpredictable
Costs of tidal energy
1. costs a lot to build 2. isn't consistent
Costs of hydropower
1. dams alter ecosystems and affect organisms 2. some fish can't survive a drastic temperature change around the dams 3. building dams and reservoirs can displace people 4. Sediments get caught in the stream 5. Unlikely to grow 6. Causes erosions or landslides
Benefits of hydropower
1. inexpensive once built 2. can reduce greenhouse gas emissions 3. yields relatively cheap electricity
Costs of solar energy
1. many regions aren't sunny enough 2. devices are expensive 3. the power only works when the sun is out
Costs of geothermal power
1. prime locations are location specific 2. high initial cost 3. Not sustainable 4. some projects can trigger earthquakes
Benefits of active solar energy
1. produces clean energy 2. can be located right where the power is needed 3. Inexhaustible renewable
Benefits of geothermal power
1. small physical footprint 2. releases no pollution 3. heat pumps save money
Benefits of wind energy
1. we are less fossil fuel dependent 2. under good conditions, produces more energy than it uses 3. Renewable 4. Clean (no CO2 emissions) 5. Windfarms reduce blackouts 6. Energy efficient 7. Easy and inexpensive to maintain 8. Inexhaustible renewable
Wind speeds are __% faster off shore
20
What two things are required to have a windfarm?
A constant wind source and an open space
What kind of interior helps passive solar energy heat a home?
A darker interior retains heat
Biodiesel
A diesel substitute produced by extracting and chemically altering oil from plants
What parts do all windmills have?
A gearbox, turbine, generator, and blades
ocean thermal energy conversion (OTEC)
A process that converts the thermal energy in ocean water to electrical energy that people can use
What three things does thermal mass do?
Absorbs, retains and reheats
Biomass combustion energy conversions
Chemical to thermal
Active solar energy conversions
Electromagnetic to thermal to mechanical to electrical
Are windmills faster or slower off shore?
Faster because of the higher winds near the ocean
How does the sun get its energy?
From thermonuclear fusion
What can biomass be used for?
Heating, cooking, lighting, vehicle fuel, electricity generation
______ is most widely used
Hydropower
Which country uses geothermal energy the most?
Iceland
Wind energy is a direct/indirect source of energy
Indirect
How is solar energy (PASSIVE) related to the sun?
It uses the sun's heat for heating buildings
How is solar energy (ACTIVE) related to the sun?
It uses the sun's rays to produce electricity
How is wind energy related to the sun?
It's formed from the sun's uneven heating of the earth's surface
How is tidal energy related to the sun?
It's produced by the natural rise and fall of tides caused by the gravitational interaction between Earth and the sun
How can rivers generate electric power?
Kinetic energy from moving water turns turbines to generate electricity
Tidal energy conversions
Mechanical to electrical
Why is the growth of hydropower unlikely?
Most of the places that have a great opportunity for hydropower have already been dammed
How is hydrogen fuel related to the sun?
Most of the sun is made up of hydrogen
Wind energy
Moving air caused by wind pressure and the uneven heating of earth's atmosphere
Is geothermal energy related to the sun?
No
How is biomass related to the sun?
Plants absorb energy from the sun and convert this solar energy into chemical energy during the process of photosynthesis.
Hydropower energy conversions
Potential to mechanical to electrical
The most expensive energy source
Solar energy
The three categories of biomass and examples
Solid= Corn, Grain Liquids= Manure Gas= Methane
What does the reservoir behind a dam do?
Stores water
What are some key words for hydropower?
Temp. gradient, ammonia, height difference between tides, water cycle
What is the largest dam in the World and where is it?
The Three Gorges Dam in China
How is hydropower related to the sun?
The energy generated through hydropower relies on the water cycle, which is driven by the sun
Biomass
The energy we use from things that are living or were once living
What do houses need that want to use passive solar energy?
Thermal mass
How is geothermal energy used?
To heat and generate electricity
Most active solar power plants are located in the southwest of the __
US
What are some key words for geothermal energy?
Uranium, fission, bubbling mud, erosion, yellowstone national park, and magma
The rising energy source
Wind energy
Flat-plate solar collector
a device that consists of a black, heat-absorbing, metal plate in a flat box with a glass cover
Wind turbine
a device that converts the wind's kinetic energy into electrical energy
Photovoltaic (PV) Cell
a device where solar energy is converted directly into electricity
Passive solar energy
a process that involves designing a building to collect, store and distribute the sun's energy naturally
Active solar energy
a system that uses technology to move, collect and store heat derived from the sun
Concentrating solar power (CSP)
a technology that uses mirrors to focus sunlight in order to generate electricity
Ground source heat pump
a tool that takes advantage of the fact that the temperature of soil a few feet underground stays the same. It brings in warm air in the winter and cold in the summer.
Flat-plate solar collectors, or solar panels, provide a method for ____________ solar heating
active
Solar collectors carry _________ or _____
anti-freeze or water
Which of the following is NOT a part of a wind turbine? a. blades b. mirrors c. gearbox d. generator
b. mirrors
Fermentation is produced using what energy source?
biomass
The oldest human energy source
biomass
To create electricity, wind blowing into a turbine turns __________
blades that connect to a gearbox
PV cell energy examples
calculator, roadside phones
Biomass electricity generation energy conversions
chemical to thermal to mechanical to electrical
What are examples of biomass energy sources?
corn, switchgrass, manure, wood, biodiesel
Geothermal energy
deep beneath the earth's surface, high pressure combined with the breakdown of radioactive energy that creates heat. The heat is used to heat our homes and generate electricity.
Is passive solar energy an indirect/direct source?
direct
Passive solar energy does/does not generate electricity
does not
A fuel cell is a device that is used to produce...
electricity
What does a solar power plant generate?
electricity
Biomass energy
energy produced by burning organic matter, such as wood, food scraps, and alcohol
What are the two primary biofuels?
ethanol and biodiesel
What geologic feature would be found where geothermal energy is located?
geysers and hot springs
Geothermal power plants are only on top of ______ ______
hot spots
Byproducts of Hydrogen fuel
hydrogen and water
Biofuels
liquid fuels from biomass sources
The most common way to obtain hydrogen today is to extract it from ____________ which is a component of natural gas
methane
What fuel is produced when microorganisms decompose landfill wastes?
methane
Greenhouses use ______ solar heating to collect the sun's energy
passive
Offshore wind farms are becoming more common because they ___________
produce more power, due to higher elevations
PV cells are also known as __________
solar cells
CSP focuses the ____ heat to generate electricity
sun's
Biopower
the burning of biomass energy sources to generate electricity
Hydropower
the kinetic energy of moving water that turns turbines and generates electricity
Wind farm
the location where wind turbines are built in groups and powered
Tidal energy
the movement of tidal water to generate electricity. it's formed from the difference of high and low tides.
Solar energy is an indirect source of energy b/c of ___________________________
the uneven heating of earth's atmosphere and the sun's waves
Solar energy converts sunlight into _______ energy and then distributes the heat without using heat pumps
thermal
Geothermal energy conversions
thermal to mechanical to electrical
OTEC conversions
thermal to mechanical to electrical
Energy from the ocean is...
tidal and thermal
What is passive solar energy mainly used for?
to HEAT
What is a characteristic of a ground source heat pump?
underground soil temperatures remain constant all year long
Electrolysis
when water molecules are broken down into oxygen and hydrogen gases by an electric current that runs through the water
What are apertures?
windows