Plug into nature

Grade 4 Science

Content

• Energy has various forms

Curricular competencies

Questioning and predicting

• Demonstrate curiosity about the natural world

Evaluating

• Identify some simple environmental implications of theirs and others’ actions

The path of electricity

The path of hydroelectricity starts with rain and snow falling to the earth. A hydroelectric dam collects water that has run off mountains (melting snow and ice) and rainwater in a reservoir. The water is channelled through the dam by large pipes, called penstocks, to turbines. The energy of the falling water is used to turn the turbines, which generates electricity.

The electricity travels long distances over high-voltage wires called transmission lines. When transmission lines get close to a town or city, they go into substations. The electricity is then sent along the power lines we see in our communities.

Power lines are sometimes buried underground but often suspended by power poles to distribute the electricity to your neighbourhood. The grey cylinders on power poles are transformers that reduce the voltage so the electricity is safe to be sent into homes, schools and businesses. Pad-mounted transformers, the locked metal boxes you see on some street corners, are used in those areas where the power lines run underground.

Meters measure the amount of electricity that passes through them and into buildings. The electricity flows through wires to electrical outlets so we can use it to power lights, computers, devices, appliances and machines.

Energy connections to nature

We use energy every day to cook our food, heat our homes, fuel our cars, and power our lights and computers. All of the energy we use ultimately comes from the sun and earth (coal, oil, natural gas, solar, water, wind). It’s important for students to understand that our energy use affects the environment.

Fossil fuels (coal, oil and natural gas) come from underground and were formed a long time ago from the fossilized remains of plants and animals. Fossil fuels are known as non-renewable energy sources because they take millions of years to form. The burning of fossil fuels (coal, oil and natural gas) creates greenhouses gases that contribute to global warming and in turn, climate change.

In B.C., the majority of our electricity is made using the power of moving water (hydroelectricity) because large fast-moving rivers are abundant in our province. Other renewable sources of energy include the sun, the wind and geothermal sources from underground. These energy sources have less of an impact on the environment than non-renewable sources.

• Assess students’ ability to work together in small groups.
• Assess student participation and communication in class discussions.
• Assess student understanding of the environmental implications of using electricity.