Electricity Generation How Heat Energy is Transformed into Electricity This Power Point is one of a series of 5 mini lectures in support of the “Energy in the 9.3 Standard” The lecture series includes: Fossil Fuels Renewables Nuclear Energy Hydrogen Fuel Cells How Electricity is Generated All Power Points have “hot spots” that can be clicked in particular slides. These spots bring up enlargements, animations or other enhancements to the slide. Some Power Points have short video clips linked to the slide. To use these clicks, your video player software should be up to date and you must be linked to the internet. In each case, “hot spots” are identified in the notes page, and the direct link to the videos are provided.

Electricity Electricity is a secondary source of energy We must use a primary source of energy to transform it into electricity Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable nor non-renewable. Electricity is not a primary source of energy. A primary source of energy (the fuel) is transformed into electricity that we can then use to run appliances, radios, etc. For example: coal (a primary source) is burned to transform it into electricity (a secondary source) and we plug the toaster into the electric outlet to make breakfast.

Potential Energy Forms Energy Transformations— Remember what we know about energy transformations: Potential Energy Forms Kinetic Energy Forms Chemical Energy Stored Mechanical Energy Nuclear Energy Gravitational Energy Electrical Energy Radiant Energy (light and solar) Thermal Energy Motion Energy Sound Energy There are both Potential Energy Forms and Kinetic Energy Forms

Energy Transformations To Create Electricity Potential Chemical Energy Kinetic Thermal Energy Kinetic Motion Energy Kinetic Electrical Energy There are four energy transformations to create electricity. The process begins with potential chemical energy. This is energy stored within a material (like coal). The potential energy may be heated or combusted to create kinetic thermal energy. The heat (thermal energy) is then able to transform into kinetic motion energy. Like when steam hits a pinwheel, the pinwheel will turn. The motion energy is then transformed into kinetic electrical energy.

Current creates Field that wraps around wire.

An electron orbiting the nucleus creates a small magnetic field

Moving magnet creates a current Magnetic Induction Moving magnet creates a current

Electricity and Magnetism Moving charges (Current) Creates a Magnetic Field. Moving Magnets Create Current

Heat & Electricity Generation Heated water turns to high pressure steam Water is heated in the boiler Steam turns the turbine Fossil Fuel (Coal) --Combustion to heat water In the generator a coil of copper wire spins between electromagnets to create electric current Click on the hot spots for pop-up explanations: Coal is combusted to heat water. The water is heated in the boiler The hot water is turned to high pressure steam The steam turns a turbine The turbine turns a magnet wrapped in copper coil to generate electricity in the generator and sends electricity to the transformer The condenser re-circulates the cooled water. Steam condenses, water is re-circulated Source: Tennesse Valley Authority website at http://www.tva.gov/power/coalart.htm

Combustion Potential Chemical Energy Coal contains what kind of energy When coal is combusted (burned) the energy it contains is released in the form of what kind of energy ? Potential Energy Forms Kinetic Energy Forms Chemical Energy Stored Mechanical Energy Nuclear Energy Gravitational Energy Electrical Energy Radiant Energy (light and solar) Thermal Energy Motion Energy Sound Energy Ask students to use the Energy Types to answer the questions Coal contains: Potential Chemical Energy When coal is combusted (burned) the energy it contains is released in the form of: Kinetic Thermal Energy Combustion can be from a different fuel source than coal. What types of fuels can be used to create electricity? Some possible fuels used to create electricity: petroleum—oil, diesel, kerosene, jet fuel, propane; natural gas; biofuels--wood, biodiesel. Also nuclear fission has the same result of heat production which results in the creation steam to create kinetic motion energy. Wind, solar, tidal and geothermal energies can be used to create electricity without combustion. ? Kinetic Thermal Energy

Steam Kinetic Thermal Energy heats incoming water in the boiler (furnace) The heated water is turned to high pressure steam

Potential Energy Forms Turbine The High Pressure Steam turns a Turbine, transforming the kinetic thermal energy into what kind of energy ? Potential Energy Forms Kinetic Energy Forms Chemical Energy Stored Mechanical Energy Nuclear Energy Gravitational Energy Electrical Energy Radiant Energy (light and solar) Thermal Energy Motion Energy Sound Energy Kinetic Motion Energy The High Pressure Steam turns a Turbine, transforming the kinetic thermal energy into kinetic motion energy

Potential Energy Forms Kinetic Electrical Energy Generator The turbine turns a magnet surrounded by a copper coil creating electric current. Kinetic Motion Energy is transformed into what kind of energy Electrons move through the copper wires to the transformer. ? Potential Energy Forms Kinetic Energy Forms Chemical Energy Stored Mechanical Energy Nuclear Energy Gravitational Energy Electrical Energy Radiant Energy (light and solar) Thermal Energy Motion Energy Sound Energy Kinetic Motion Energy is transformed into Kinetic Electrical Energy Kinetic Electrical Energy

If your starting fuel was something different, what parts of the power plant would be the same or different? Combustion fuels (petroleum, gas, biofuels) ? Nuclear Geothermal Wind and Tidal Power All of the “combustions fuels” work very similarly to coal: petroleum—oil, diesel, kerosene, jet fuel, propane; natural gas; biofuels--wood, biodiesel. With Nuclear Fission, the fuel isn’t burned, but the fission creates heat. Nuclear electric generators use boiling water generators or pressure (steam) generators, too. With high-heat geothermal, the earth’s heat creates the steam or boiling water, working similarly to the diagram. Wind and tidal power can be used to create electricity without combustion. With these technologies, nothing is burned and no heat is produced. The Kinetic motion energy of wind, and tidal move a turbine. With solar photovoltaic systems, electrons feed electrical energy directly into the transformer. Solar Photovoltaic