Transcript File
Custom Energy Lesson Created by Mr. Chou Energy We Use • What is the most common and useful form of energy that we use that runs through all our buildings and electronics? • Electricity! • Electric Energy is the most common and useful form of energy that we use because it is relatively easy to transmit and to use. Electrical Generating Plants • Electrical generating plants do not create energy. Instead, they change other forms of energy into electricity using the concept of… • Energy Transformation, which is a change from one form of energy to another. ☺ For Example… • When a car’s engine burns fuel, stored energy in the fuel is released and converted into mechanical or kinetic energy of moving engine parts. "Aut viam inveniam aut faciam" • The Latin phrase above means: “Either I will find a way, or I will make one.” • Since our power grid is wired primarily for electrical energy, we need a way to transform all other forms of energy into electrical energy before we can use it. • The way we make this happen is through the use of an invention called turbines. Turbines and How They Work • Turbines are machines used to produce continuous power in which a wheel or rotor, typically fitted with vanes, is made to revolve by a fast moving flow of water, steam, gas, air, or other fluid. Converting Different Sources of Energy to Create Electricity • Chemical • Nuclear • Mechanical • Radiant • Thermal Chemical Energy 😊 • Many energy sources commonly used by humans are forms of chemical energy. They are usually labeled “fuels.” The way to use the chemical energy of fuels is by burning them in a process called combustion. During combustion, chemical bonds are broken and energy is released in the form of heat. That heat can then be used to heat a fluid to power a turbine. Renewable vs. Non-renewable • When an energy source is non-renewable, it means that it cannot be replaced within a useful time frame. • Ex. Fossil fuels take hundreds of millions of years to form. • Coal & Oil (or Petroleum) Formation Nuclear Energy 😊 • In a nuclear power plant, the heat is released from nuclear fission reactions, or the splitting of atom’s nucleus into two nuclei. That heat is used to turn water into steam, which is used to turn the blades of a turbine to generate electricity. Mechanical Energy – Hydropower • Hydroelectric Energy – produces energy through flowing water to turn a turbine. Mechanical Energy – Wind Power • Wind Energy – produces electricity through air flow which turns a turbine. Radiant Energy – Solar Energy 😊 • Solar Energy or Solar Radiation – The sun constantly gives off energy in the form of light and heat, which can be converted to electricity either directly through solar cells or indirectly by heating water to create steam to turn turbines. Thermal Energy - Geothermal • Geothermal Energy – uses the Earth’s internal heat to heat water and create steam that can turn a turbine to create an electric current. How Do We Choose Which Source Is Best? • Factors to consider: • Efficiency – the percentage of energy that is actually used to perform work. The less amount of energy that is “lost” as heat, the greater the efficiency. Example: A thick blanket is more efficient than a thin blanket because it traps in more of the energy or heat that would have been lost. • Pollution/Safety – The negative effects on the environment or people. Ex. Solar, wind, and geothermal energy all do not produce any air pollution. • Practicality – Is the location suitable for the type of energy source required? Ex. Wind energy requires an area with constant wind and Hydroelectric energy requires an area with constant water flow. Efficiency • When we transform energy from one form to another, the total energy within that system is always constant or equal. This follows the law of: • • Conservation of Energy – Energy can neither be created or destroyed, but it can change from one form of energy to another. During any transformation in energy, some energy is always “lost” in the form of heat. Therefore… • If… Efficiency – the percentage of energy that is actually used to perform work. The less amount of energy that is “lost” as heat, the greater the efficiency. Example: A thick blanket is more efficient than a thin blanket because it traps in more of the energy or heat that would have been lost. • Then… The higher the efficiency of the energy transfer, the better! Pollution • The presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects. • Fossil Fuels – Combustion causes pollution. • Most pollution – Coal • Least pollution – Gas • Some energy sources produce NO AIR POLLUTION: • Solar, wind, and geothermal. • **Wind energy can cause sound pollution sometimes. Summary of Earth’s Energy Systems • All the Energy in the Earth: • https://www.youtube.com/watch?v=fHztd6k5ZXY • All the Energy in the Universe is…: • https://www.youtube.com/watch?v=dmcevC55K3s