How is Electrical Energy Part of Your World? PDF

BC Science Connections 9 Unit 3: Electric current is the flow of electric charge Topic 3.1: How is electrical energy part of your world? Electrical energy has many applications. Many different types of energy can be transformed into electrical energy. Electrical energy is...

BC Science Connections 9 Unit 3: Electric current is the flow of electric charge Topic 3.1: How is electrical energy part of your world? Electrical energy has many applications. Many different types of energy can be transformed into electrical energy. Electrical energy is generated in different ways from different sources.  Concept 1: Electrical energy has many applications. Electrical energy: the energy of charged particles What uses electrical energy? The human body Technology (touch- sensitive screens, robots, maglev trains) Figure 3.1  Electrical Energy Applications: The Human Body The human body uses electrical energy Moving your eyes to read relies on electrical signals in your muscle and nerve cells Electrical signals help maintain Figure 3.1 breathing and heat beat  Electrical Energy Applications: Technology Different types of technology use electrical energy Touch-sensitive screens Robots (made of flexible plastic that response to electrical signals like your own muscles) Maglev trains (hover above electrified coils along tracks) Figure 3.1  Concept 2: Many different types of energy can be transformed into electrical energy. Energy is neither created or destroyed It is transformed from one kind of energy to another kind of energy Many types of energy can be transformed into electrical energy  Energy That Can Be Transformed Into Electrical Energy: Mechanical Energy Mechanical energy: The sum of kinetic energy and potential energy Kinetic energy: Energy of motion Potential energy: Stored energy that a system has due to its position or condition Example: Water at the top of a waterfall, just before it falls, has potential energy because of its position, and kinetic energy because it is moving  Energy That Can Be Transformed Into Electrical Energy: Chemical Energy Chemical energy: Energy stored in chemical bonds, and released when a chemical reaction occurs Batteries store chemical energy Chemical energy stored in animals and plants is called biomass Fossil fuels (coal, oil, natural gas) store chemical energy Figure 3.2  Energy That Can Be Transformed Into Electrical Energy: Solar Energy Solar energy: Energy carried by electromagnetic radiation given off by the Sun Fossil fuels and biomass result form energy from the Sun being captured by plants and plant-like Figure 3.2 organisms  Energy That Can Be Transformed Into Electrical Energy: Nuclear Energy Nuclear energy: Energy generated by forming new atoms Nuclear fusion: New atoms are made as smaller atoms collide and fuse (occur in the Sun and stars) Nuclear fission: New atoms are made by splitting larger atoms (carried out in reactors Figure 3.2 on Earth) Figure 3.2  Energy That Can Be Transformed Into Electrical Energy: Thermal Energy Thermal energy: Energy due to the rapid motion of particles that make up an object; detected as heat Sources include nuclear reactions or from Earth’s interior (geothermal energy), where steam and hot water form naturally Figure 3.2 Example: Geysers, volcanoes, hot springs  Discussion Questions 1. Explain the different between kinetic energy and potential energy. 2. Describe the relationship among solar energy, biomass, and fossil fuels.  Concept 3: Electrical energy is generated in different ways from different sources. Different types of energy can be transformed into electrical energy Most of the electrical energy in Canada is generated by transforming kinetic energy into electric energy Source of kinetic energy may be moving water, wind, or moving steam produced by nuclear reactions or burning fossil fuels  Kinetic Energy to Electrical Energy: Generator System Generator system: A system that transforms kinetic energy to electrical energy Turbine: Steam, water, or wind cause the turbine to spin Shaft: As the turbine spins, the shaft spins Generator: Kinetic energy of the spinning shaft is transformed into electrical energy inside the generator Figure 3.3 Kinetic Energy to Electrical Energy: Generator System (continued) Figure 3.3  Generating Electrical Energy in Canada Most of the electrical energy in Canada comes from river flow, fossil fuels, and nuclear reactions British Columbia: River flow is the main source (hydroelectric energy) Also uses fossil fuels No nuclear reactors  Hydroelectric Energy from River Flow Two systems generate hydroelectric energy: Dam station (shown below) Water stored behind dam has potential energy As water flows downhill, it gains kinetic energy, which turns a turbine connected to a generator Run-of-river station Water flowing freely in a river turns a turbine Figure 3.4  Electrical Energy from Fossil Fuels Generating station: Thermal energy from burning coal is used to boil water into steam Pressure associated with moving steam turns the blades of turbines connected to generators Figure 3.4  Electrical Energy from Nuclear Reactions Nuclear reactor: Uranium or plutonium atoms undergo fission reactions Splitting one atom sets off a chain reaction that causes more atoms to split, which releases energy Most of the energy is thermal energy, which is used to boil water into steam Pressure from the moving steam turns turbines connected to generators Figure 3.4  Generating Electrical Energy from Other Energy Sources Other energy sources include: Wind Sunlight Geothermal sources Waves and Tides  Electrical Energy from Wind Kinetic energy of wind is transformed into electrical energy as the moving air turns the turbine of a generator system Wind turbines have an anemometer is used to measure wind speed Figure 3.5  Electrical Energy from Sunlight Photovoltaic cells transform the energy of visible light to electrical energy When visible light strikes electrons in the photovoltaic cells, the electrons absorb enough energy to flow freely and generate electrical energy Figure 3.6 Electrical Energy from Geothermal Sources Where Earth’s crust is thin and molten rock comes close to the surface, hot steam can be used to turn turbines to generate electrical energy Figure 3.7  Electrical Energy from Waves and Tides Tides and the rise and fall of waves can turn turbines to generate electrical energy Figure 3.8  Discussion Questions 1. List three key parts of a generator system. Briefly describe their functions. 2. Use a flowchart to explain how moving water can generate electricity.  Topic 3.1 Summary: How is electrical energy part of your world? Electrical energy has many applications. Many different types of energy can be transformed into electrical energy. Electrical energy is generated in different ways from different sources.