alternative energies. before the bell rings… get out your hw assignment due today. get out your...
TRANSCRIPT
Alternative Energies
Before the bell rings… Get out your HW assignment due today. Get out your notes and answer the following…
What are the three fossil fuels, give an advantage and disadvantage of each?
What is a major issue facing us using fossil fuels as a main source of energy?
What are alternative energies? List as many as you can.
Before the bell rings…A chance to redeem yourself on the quiz!
Turn in your Webquest on the stool in the middle of the room if you did not already
Get out your notes and answer the 2 Questions… What are alternative energies? List as many as you can, you should at least know
6, think of you webquest.
Alternative Energies Energies that are not
fossil fuels. Most are renewable.
Nuclear is NOT renewable but IS an alternative
The following are renewable: hydropower, solar, wind, geothermal, biomass, hydrogen, tidal, and wave.
About 10% of today’s energy in the U.S. is renewable(not including nuclear).
Why did we start to research alternative energies?
Research toward alternative energies started in the 70’s due to the oil embargo and are continuing today due to foreign oil dependency and environmental concerns.
Hydropower This uses the mechanical
power of flowing water to generate electricity. Power depends on the amount of water (flow) and the distance it falls (head). (diagram pg. 450)
Accounts for 42 % of U.S. renewable energies and is the largest renewable source for electricity – 7%.
Why can’t we increase hydroelectric usage?
Will not increase in the U.S. because most suitable sites have been used.
Hydropower-Impacts
Renewable, nonpolluting, and reliable, BUT….
Costly to build and funds to build new dams have not been approved in more than a decade.
Dams disrupt the environment and create different habitats.
Block fish migration (fish lifts) Dams can fill with sediment
becoming useless if not maintained.
Hydropower is on the decline
Fish Ladder Video
Natural Fish Ladder Video
Dam Videos
Dam Removal- https://www.youtube.com/watch?v=4LxMHmw3Z-U
3 Gorges Dam- Full capacity- https://www.youtube.com/watch?v=sB6SwPHPEtQ
The Rundown on Wind Use of wind to spin turbine to
generate electricity. Researches are looking for
ways to store energy and reduce cost.
Fastest growing energy source in the world. (costal Europe)
Electricity is almost as cheap as fossil fuel in areas with strong winds.
Most effective on coasts, mountains, and open plains
Winds farms now exist in PA, West Virginia, and New York
Accounts for only 1% of our alternative energy.
Wind Impacts Few environmental impacts (noise, space, damage
to bats and birds) Some argue they are not aesthetically pleasing Nantucket Video No air pollution
Why is wind energy limited? Limited due to varying winds…
Biomass The burning of wood,
agricultural wastes, sewage, algae, and processed trash. Also includes fuels made from organic matter.
Various methods are used to create fuels that can be used for heating or transportation. (could possibly replace petroleum)
Corn, Sugar, and grains can be converted through fermentation by yeast to produce ethanol. (can be blended with gasoline)
Ethanol
Usually put more energy into making it then you get out of the product itself!!!!
Why do you think people still produce it?
Biomass Biodiesel is a substitute for
diesel engines and is made from animal fat or vegetable oils.
Use is increasing with new technologies.
Accounts for close to 50% of alternative energy in this country. Major source for Hawaii.
Biodiesel
Bagasse-Hawaii
What are the impacts of Biomass? Some air pollution. Processing of
some organic wastes release hazardous chemicals.
Responsible for forest destruction and soil erosion in rainforests. (burning of wood)
Geothermal Uses the natural heat
(dry heat, steam, or hot rock) tapped in the earth to heat homes or produce electricity. (diagram pg. 476)
Power plants must be near the source because too much energy is lost during transportation.
Only Hawaii, Nevada, Utah, and California have the potential
Accounts for 6% of our renewable energy.
What are the effects of Geothermal? It is limited to certain areas. Nothing is burned so there is limited air pollution. Harmful gases can sometime be vented with heat
and land surfaces may collapse.
Tidal Converts the
mechanical energy from ocean tides to electricity.
Limited to coastal regions and therefore will never be a major energy source in this country. (Canada, China, and France)
Wave Waves force water up a large tower pushing the
air up over a turbine to generate electricity. (Norway)
https://www.youtube.com/watch?v=gcStpg3i5V8
Hydrogen FuelThe changing of hydrogen gas into a
fuel source (gas or liquid)Makes up ¾ the mass of the universe
and is the lightest element.Requires water (methane) and water
vapor is the only product given off when burned
The Department of Energy is looking into expanding its use (fuel cell technology)
HFuel It would require new equipment and
engines to burn it (fuel cells) Hydrogen fueled cars have been made. * Check out this web site:
www.eere.energy.gov/hydrogenandfuelcells/
Great Video about Hydrogen Fuel Cell Cars
ImpactsPollution free. It is too expensive and difficult to
store. It could one day replace gasoline
engines and our dependency on foreign oil.
A transition from fossil fuels to hydrogen fuel will take a lot of time and money.
This is the so-called “chicken and egg” problem that hydrogen developers are working hard to solve. Namely: who will buy hydrogen cars if there are no refueling stations? And who will pay to build a refueling station if there are no cars and customers?