Electrical Energy Applications

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 is the energy of charged particles.

What Uses Electrical Energy?

• 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 breathing and heart beat.
• Different types of technology use electrical energy.
• Touch-sensitive screens are an example of technology that uses electrical energy.
• Robots, made of flexible plastic that responds to electrical signals, are an example of technology that uses electrical energy.
• Maglev trains, which hover above electrified coils along tracks, are an example of technology that uses electrical energy.

Concept 2: Many Different Types of Energy can be Transformed Into Electrical Energy

• Energy is neither created nor destroyed.
• Energy is transformed from one kind of energy to another kind of energy.
• Many types of energy can be transformed into electrical energy.

Mechanical Energy

• Mechanical energy is the sum of kinetic and potential energy.
• Kinetic energy is the energy of movement.
• Potential energy is stored energy that a system has due to its position or condition.
• Water at the top of a waterfall has potential energy because of its position, and kinetic energy because it is moving.
• Mechanical energy = Kinetic energy + potential energy
• Combine how fast something is moving (kinetic) with how high or stretched it is (potential)
• Potential energy is energy of possible movement.
• The more work or movement it could cause if released, the more potential energy it has.

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.
• Sources 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

• A generator is a system that transforms kinetic energy to electrical energy.
• The turbine is moved by steam, water, or wind.
• The shaft spins as the turbine spins.
• The generator transforms kinetic energy of the spinning shaft into electrical energy inside the generator.

Generating Electrical Energy in Canada

• Most of the electrical energy in Canada comes from river flow, fossil fuels, and nuclear reactions.
• In British Columbia, river flow is the main source of electrical energy, known as hydroelectric energy.
• British Columbia also uses fossil fuels.
• British Columbia does not use nuclear reactors.

Electric Energy from River Flow

• Two systems generate hydroelectric energy: dam stations and run-of-river stations.
• Dam stations store water behind a dam, which has potential energy.
• As water flows downhill, it gains kinetic energy, which turns a turbine connected to a generator.
• Run-of-river stations use water flowing freely in a river to turn a turbine.

Electrical Energy from Fossil Fuels

• Generating stations:
• Fuel is burned to boil water and make steam.
• Thermal energy from burning coal is used to boil water into steam.
• The pressure associated with moving steam turns the blades of turbines connected to generators.

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, releasing 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.

Generating Electrical Energy from Other Energy Sources

Wind

• Kinetic energy of the wind is transformed into electrical energy as the moving air turns the turbine of a generator system.
• Wind turbines use an anemometer to measure wind speed.

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.

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.

Waves and Tides

• Tides and the rise and fall of waves can turn turbines to generate electrical energy.

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.

Chemical Energy

• Is energy stored in chemical bonds.
• Batteries store chemical energy.
• Chemical energy stored in animals and plants is called biomass.
• Fossil fuels (coal, oil, natural gas) store chemical 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 organisms.

Nuclear Energy

• Nuclear energy is generated by forming new atoms.
• Nuclear fusion creates new atoms as smaller atoms collide and fuse, occurring in the Sun and stars.
• Nuclear fission creates new atoms by splitting larger atoms, carried out in reactors on Earth.

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.

• Geysers, volcanoes, and hot springs are examples of thermal energy.

• Biomass is chemical energy stored in animals and plants

• Fossil fuels are created from millions of years old plants and animals

• Fossil fuels are really old, buried biomass = ancient solar energy