TEK 5.7C Identify alternative energy resources such as wind, solar, hydroelectric, geothermal, and biofuels.
Alternative Energy Resources
Alternative Energy Resources are energy resources that can be used instead of nonrenewable resources or fossil fuels. They produce energy without the consequence of the burning of fossil fuels (coal, oil, natural gas) to provide electricity, heat, and run cars.
There are 5 types of Alternative Energy Resources-biofuel-hydroelectric-geothermal-wind-solar
Solar Power:
Solar energy is energy that comes from the sun. This energy gives us light and heat. We can also use sunlight to make electricity.
Solar cells are one way to use the sun's energy. Solar cells change sunlight to electricity. Lots of cells are put together in a solar panel. When sunlight hits the panel, it generates electricity. Many people are putting solar panels on their roofs to help power their homes and businesses.
What if there is no sun? Since there is no sun at night you can purchase a battery that can store electricity.
You can find solar panels in large fields like at the Denver International Airport.
You also find solar panels on the roofs of buildings and homes.
Advantages:Solar energy will not run out, and does not pollute.
Disadvantages:It takes a lot of space, and is expensive to buy and install. It also needs bright light to work.
Wind Power
How can we use wind to make electricity?
The wind blows directly onto the blade of the turbine, much like wind turns a pinwheel. The turbine turns the generator to make electricity.
Turbines are built in windy areas - across open plains, on smooth hills, near shorelines, and between mountain gaps.
Click the wind turbine to take a tour of a wind farm.
A wind farm is an area where huge metal fans are set up to catch the wind. Wind turns the blades connected to a generator which makes electricity. This is the opposite of a regular fan.
Wind energy does not pollute, but wind turbines are expensive, and the strength of the wind isn't constant. Some areas are not windy enough to use wind power. Electrical energy produced by wind is more expensive than from other sources.
Hydroelectric Power
What is hydroelectric power? Hint...hydro means water. Hydroelectric power is electricity produced by moving water.Falling water can be very forceful. River water can fall over waterfalls and be used to make electricity. Hydroelectric power plants can be built at the bottom of a dam to take advantage of the high pressure of the water at the bottom of the reservoir (lake). The water is funneled through a tunnel. The pressure of the water turns the blades of the turbine, which turns a generator making electricity.
Fun fact:One of the earliest generating stations was built in 1896 at the bottom of Niagara Falls.
A dam could be built across the river. Water moving through the dam turns a generator which makes electricity. We call this hydroelectric power.
Rivers can be used as an alternative energy resource.
Hydroelectric Dam
Biofuel
Biofuel is fuel that comes from plants. Plants contains stored energy from the sun. Plants absorb the sun's energy in a process called photosynthesis. The chemical energy in plants gets passed on to animals and people that eat them.
Today, we can burn garbage in special waste-to-energy plants and use its heat energy to make steam to heat buildings or to generate electricity.
There are about 90 waste-to-energy plants in the United States. These plants generate enough electricity to supply almost 3 million households.
Biofuels are made in two ways. One way is to use plants that are high in sugar or starch and make them into ethanol. Corn, sugar cane, and sweet sorghum are often used to make ethanol. Ethanol can be used like gasoline in some car engines. More often, it is combined with gasoline to make a cleaner fuel.
Another way is to use plants that contain lots of vegetable oil and use them to make biodiesel. Certain palm trees and soybeans are often used in this way. Biodiesel can be used in diesel engines. Pure vegetable oil can also be used in certain engines. Both are usually more expensive than the fossil fuels that they replace, but they are also cleaner-burning fuels, producing fewer air pollutants.
Fryer FlyerThe "Fryer Flyer" is a green school bus that runs on waste vegetable oil (WVO - post-consumer grease which is often disposed of improperly, clogging our sewers and waste water treatment facilities). Dallas County Schools collects the WVO that is donated by local restaurants and food manufacturers. They then transport it to their plant, where it is cleaned and contaminants are removed through a filtering process. Once the WVO is clear of debris and foreign substances, it is ready to be used as fuel or processed into biodiesel, also known as B100. The use of WVO and B100 reduces the production of greenhouse gases, particulate matter and other pollutants which are harmful to the environment.
Biofuels
This bus runs on soybean bio-diesel. Bio-diesel is made from vegetable oils, animal fats or recycled greases.
Geothermal
What is geothermal energy? Geo means Earth and thermal means heat. Geothermal energy is heat from the Earth's hot interior.
In some places the Earth's heat can make steam for example near volcanos or near moving earth plates. Sometimes the steam can be taken directly from the earth.
Geothermal power plants use deep wells to tap into underground reservoirs of hot water. These wells bring the hot water to the surface. There it produces steam to generate electricity. The cooled water is returned underground to be heated again. Then, the cycle starts over.
Geothermal Energy
