Understanding grid systems
Explore how electricity is generated and distributed through grid systems, to even the most remote communities in B.C.
Overview
Explore how electricity is generated and distributed in B.C. Students learn how electricity is distributed using integrated and isolated grids and the challenges of distributing electricity to remote areas. Students will map their own grid system to put this knowledge into practice.
Instructions
What you'll need
- “Energy distribution” slideshow
- "Build an electrical grid" handout, one copy per student
- "Electrical grid 101" video
- "Tŝilhqot’in solar farm" video
- Digital projector and screen
- Pull up the “Energy distribution” slideshow and start at slide 2 with a discussion on how different types of energy are distributed. For example, fossil fuels, such as coal, oil, and natural gas, are distributed by trucks, trains, tankers and pipelines, and electricity moves through transmission lines. Explain that electricity is a secondary energy source and needs a primary energy to generate it, like fossil fuels or renewable energy such as water, solar or wind.
- At slide 3, engage students to consider the concept of a low carbon future, where we reduce our use of fossil fuels. Discuss the climate crisis and why we need to move away from using fossil fuels and towards electricity generated using renewable energy.
- At slide 4, watch the "Electrical grid 101" video to understand how electricity is distributed, familiarizing students with terms like generation, distribution, transmission, and transformer.
- At slide 5, ask students to identify the nine labels on the diagram. Slide 6 reveals the terms and definitions.
- Slide 7 shows an image of the electrical grid system in B.C. To find a larger version, which will allow you to zoom in, go to B.C. Electrical Transmission System. Ask students to locate the main integrated grid, and the smaller isolated grids in small communities.
- At slide 8, invite students to brainstorm the challenges of distributing electricity like geography of the land, distribution of population, and distances between communities.
- At slide 9, discuss that an isolated grid is separate from the main integrated grid, and it generates and distributes its own electricity. Consider why communities have isolated grids, like an isolated, small population and geographical challenges, including mountains, bodies of water, and distance. Discuss the possible advantages and disadvantage, like having more control over the energy generation, but less robust system, if there are outages.
- At slide 10, consider what extra challenges there are with distributing renewable electricity, like where it is generated and where it is used. Many kinds of renewable energy must be generated in the most effective places, like where there is a large river for a dam, or in a windy area. Other challenges for renewables like solar include evening peak usage times when energy cannot be generated. When using power that is generated only at certain times, for example when the wind is blowing, a storage system becomes necessary.
- At slide 11 watch "Tŝilhqot’in solar farm" video that highlights how the Tŝilhqot’in community, near Hanceville, B.C., built a solar farm to reduce reliance on diesel.
- At slide 12, discuss different methods of energy storage, like batteries, hydroelectricity in a dam, and thermal storage in concrete or water. Students can discuss whether there are other ways that electricity can be stored, to help address gaps between peak demand and supply.
- At slide 13, provide each student with the "Build an electrical grid" handout. Working individually or in small groups, students start by drawing a map, with various geographical obstacles and communities that are long distances apart. Students then build a grid, including all the parts of an electrical grid. Students will also write a short analysis to justify their choices of locations, grid routes and renewable energy types.
Modify or extend this activity
- Pull up the “Sharing energy” activity to explore how energy sharing and green solutions can save energy, building community connection and robustness.
- Read BC Hydro’s Electrification plan to see how we can meet the greenhouse gas reduction targets through the electrification grid in B.C.
- Research other examples of Indigenous-led renewable energy projects in B.C. Refer to New relationship trust or find your own sources.
Curriculum Fit
Science 10
Big ideas
- Energy is conserved, and its transformation can affect living things and the environment
Content
- Local and global impacts of energy transformations from technologies
Curricular competencies
Questioning and predicting
- Demonstrate a sustained intellectual curiosity about a scientific topic or problem of personal interest
Processing and analyzing data and information
- Apply First Peoples perspectives and knowledge, other ways of knowing, and local knowledge as sources of information
Communicating
- Communicate scientific ideas, claims, information, and perhaps a suggested course of action, for a specific purpose and audience
Social Studies 10
Big ideas
- The development of political institutions is influenced by economic, social, ideological, and geographic factors
Content
- Environmental, political & economic policies: environmental issues including climate change and renewable energy
Curricular competencies
- Use Social Studies inquiry processes and skills to ask questions; gather, interpret, and analyze ideas and data; and communicate findings and decisions
Technology Explorations 10
Big ideas
- Social, ethical, and sustainability considerations impact design
Content
- Alternate energy sources
Curricular competencies
Applied design - Ideating
- Critically analyze and prioritize competing factors to meet community needs for preferred futures
Teaching Notes
Distribution grid in B.C.
BC Hydro generates power by harnessing the power of moving or falling water to produce mechanical/electrical energy. BC Hydro generates over 43,000 gigawatt hours of electricity annually to supply more than 1.6 million residential, commercial and industrial customers. This power is delivered using an interconnected system of over 73,000 kilometres of transmission and distribution lines.
So how do we generate this power? The process begins before electricity even reaches customers. The steps to generating electricity from a dam and how it is transported are outlined below.
- Hydro dam: There is potential energy stored in a water reservoir behind a dam. It is converted to kinetic energy when the water starts flowing down the penstock, from the dam. This kinetic energy is used to turn a turbine.
- Generator: The falling water strikes a series of blades attached around a shaft which converts kinetic energy to mechanical energy and causes the turbine to rotate. The shaft is attached to a generator, so that when the turbine turns, the generator is driven. The generator converts the turbine's mechanical energy into electric energy.
- Step-up transformer: Voltage is the pressure that makes electricity flow. Generators usually produce electricity with a low voltage. In order for the transmission lines to carry the electricity efficiently over long distances, the low generator voltage is increased to a higher transmission voltage by a step-up transformer.
- Grid high voltage transmission lines: Usually supported by tall metal towers, carry high voltage electricity over long distances.
- Terminal stations: Control power flow on grid transmission lines and reduce the grid voltage to sub-transmission voltage.
- Sub-transmission lines: Sub-transmission lines supply power from terminal stations to large industrial customers or distribution substations.
- Customer use: Electric energy can be sold at transmission voltage to users of large amounts who own and operate their own substations. Most customers, however, are unable to accept energy at transmission voltage, and require that it be stepped down in a transformer.
- Distribution substation: A system of transformers, meters, and control and protective devices. At a substation, transmission voltage is reduced to lower voltages for distribution to residential, commercial, and small and medium industrial customers.
Energy storage
Energy can be stored in a variety of ways, including (excerpt from EPA electricity storage):
- Pumped hydroelectric: Electricity is used to pump water up to a reservoir. When water is released from the reservoir, it flows down through a turbine to generate electricity.
- Compressed air: Electricity is used to compress air at up to 1,000 pounds per square inch and store it, often in underground caverns. When electricity demand is high, the pressurized air is released to generate electricity through an expansion turbine generator.
- Flywheels: Electricity is used to accelerate a flywheel (a type of rotor) through which the energy is conserved as kinetic rotational energy. When the energy is needed, the spinning force of the flywheel is used to turn a generator. Some flywheels use magnetic bearings, operate in a vacuum to reduce drag, and can attain rotational speeds up to 60,000 revolutions per minute.
- Batteries: Similar to common rechargeable batteries, very large batteries can store electricity until it is needed. These systems can use lithium ion, lead acid, lithium iron or other battery technologies.
- Thermal energy storage: Electricity can be used to produce thermal energy, which can be stored until it is needed. For example, electricity can be used to produce chilled water or ice during times of low demand and later used for cooling during periods of peak electricity consumption.
Learn more about the Tŝilhqot’in solar farm.
B.C. is powered by water
In B.C., we have a unique advantage. The province’s natural landscape has allowed us to generate and deliver clean, renewable power to B.C. residents for decades. And as we look to the future, BC Hydro has an ambitious goal to do more.
Our plan to electrify B.C.
BC Hydro will be instrumental in building a sustainable economy in B.C. We’ll continue to support conservation efforts, while also offering new programs and incentives to help British Columbians make the switch from fossil fuels to clean hydroelectricity to power their homes, businesses, and vehicles. We’ll also help to attract new energy-intensive industries to B.C. and offer programs to reduce the time and costs for new customers to get connected to our grid.
Our goal is to reduce greenhouse gas emissions in the province by 900,000 tonnes per year by April 2026 – that’s around the same as taking 200,000 gas-powered cars off the road for one year. Our Electrification plan outlines how we’ll get there.
Assessment
- Assess students’ understanding of the parts of the electrical grid in distributing how and low voltage electricity throughout B.C.
- Assess students’ critical thinking skills and participation in the class discussions.
- Assess students’ creativity and communication skill in developing their electricity grids.
Downloads
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