How it Works
Wind and hydro power rely on this pair of machines to make electricity.
Turbine and generator.
This is the name for wind farms in the ocean.
Off-shore wind farms.
In addition to generating electricity, dams can be used to control this.
What is flooding?
True or false: Wind farms are loud.
True
Explain the meaning of the term Renewable Energy.
Energy generated by a source that naturally will not run out and is constantly replenished.
Describe the difference between wind turbines and fans.
Fans use energy to make wind; wind turbines use wind to make energy.
In many small machines a fuel cell acts similar to a ______, by providing a portable source of electricity.
Battery
Fuel cells are considered a good renewable energy because the only byproducts of the reaction are electricity and this.
What is water?
Dams create problems for fish. One way to help fish pass safely over a dam is through this, which is a series of pools that act as steps for the fish to jump over the dam.
What is a fish ladder?
This is needed to make the chemical reaction in the fuel cell fast enough to create electricity.
A catalyst
Fuel cells create energy when these two gases interact in the fuel cell.
What are hydrogen and oxygen?
In a hydro-electric power plant, this is hooked up to a generator and is spun by the force of the flowing water.
What is a turbine?
True or False: Fuel cell powered cars are less efficient than gasoline powered cars.
False - Fuel cells are 2-3x more efficient.
Dams are often made of this material, which is known for contributing greenhouse gases to the atmosphere.
Concrete.
The sun is a renewable resource because it is always producing these two types of energy.
What are heat energy and light energy?
Solar energy can be passive or active. To generate active solar energy, you need these, which convert sunlight into electricity.
What are photovoltaic cells?
Solar thermal energy is energy made from the sun's ______.
Heat.
What is a hybrid energy system? Given an example of two energies that would work well in such a system.
A hybrid energy system is when two energies work together to generate the energy needs.
Hydro and solar: on sunny days, the sun provides energy, on rainy days, the hydro system would provide more power.
Solar and wind: on sunny days, the sun provides energy, on stormy days, the wind system would provide power.
Solar and fuel cell: A solar car would have a fuel cell as a back up power source.
Solar panels are not very efficient. They only convert this percentage of the sun's energy into electricity.
5-15%
True or false: Wind is generated when the air over water heats up and rises and the cooler air over the land is pulled in to fill its place.
False: Air over land heats faster and rises pulling cooler air into place.
This is the name for the type of hydro-electric plant that generates energy from the force of the water flowing downstream.
What is run-of-river?
What is baseload power and why is solar energy not a good source of baseload power?
Baseload power is the minimum amount of power needed in the grid at any given time. Solar is not a good source of this because it is not consistent.
Tax incentives are a way for the government to fund research in renewable energy. Explain how this works.
If someone does research, their taxes are lowered based on the costs of their research. They pay the same amount of money, but less money is for taxes, so more can be for research.
A big problem with renewable energy is its intermittency. What does this mean? Why it is a problem for wind, solar and hydro and not for fuel cells or fossil fuels?
Intermittent means not happening consistently. This is a problem because wind, sun and water might not be strong every day. Fossil fuels and fuel cells have stored energy.
What is the difference between active and passive solar energy?
Active is solar energy is generated by using machines to turn solar energy into electricity. Passive is solar energy is the heat and light that come directly from the sun.