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Wind turbines with energy storage system

Wind turbines with energy storage system (Petmal, iStockphoto)

STEM in Context

Can You Store Electricity for Later?

Geoff Osborne

Summary

Sometimes, power plants make too much electricity. Energy storage technologies can help! They store the extra electricity and release it when demand goes up.

You probably use a lot of electricity every day. You might even be using it to read this article! We use different amounts of electricity throughout the day. At times, we use little. At other times, we use a lot. 
Sometimes, power plants generate more electricity than we need. If we don’t use it, it goes to waste. That’s because we can’t store electrical energy.

How can we avoid wasting it? Well, we can convert it into other forms of energy that can be stored.  For example, batteries can convert electrical energy into chemical potential energy. Other systems can convert electrical energy other types of energy. Examples include mechanical and gravitational potential energy. We can convert them all into electrical energy when we need it.

Let’s look at how some energy storage technologies work.

Did you know?

The energy storage market is growing. Researchers project that it will be 13 times bigger in 2024 than it was in 2019!

What is Chemical Potential Energy Storage? 

Batteries consist of one or more electrochemical cells. These cells can store chemical energy. They can also convert it to electrical energy.

You probably use batteries a lot. Maybe you have a flashlight powered by alkaline batteries. Smartphones and laptop computers runs on lithium-ion batteries. But batteries can be much bigger than the ones in your devices.

Large-scale energy storage uses two main types of batteries

  • Solid-state batteries store energy in a solid electrolyte
  • Flow batteries store energy in a liquid electrolyte
     

Did you know?

Microbial fuel cells  produce energy from bacteria! 

What is Mechanical Potential Energy Storage? 

A flywheel is a mechanical device. It rotates and stores energy. First, electrical energy is used to make it spin. The spinning creates kinetic energy. Then the electrical energy gets turned off. But because of inertia, the flywheel will keep spinning. Later, you can turn the kinetic energy back into electrical energy. 

Did you know?

Flywheels can rotate at up to 60 000 revolutions per minute! 

Short video on how a commercial energy storage company uses a flywheel (0:01:16).

 

What is Gravitational Potential Energy Storage?

There are many ways to store energy on a large scale. But pumped hydroelectric energy is the most popular. It’s used at hydroelectric power plants. A pump and a reservoir control how much water reaches the turbine.

Pumped-hydro energy systems pump water into a holding area called a reservoir.  This reservoir is located above the turbine. The water gets released when more energy is needed. Gravity pulls the water down. This spins the turbine and makes electricity. 

Usually, water gets pumped to the reservoir when energy demand is low. Water gets released when energy demand is high. 

This video from Hydro Tasmania, explains how pumped hydro works (2:22 min.).

 

Energy storage technology is improving. And it's making power systems more reliable and efficient. Try to find out more about your local electricity system. Does it use energy storage? 

Starting Points

Connecting and Relating
  • How much of your day-to-day living involves the use of electrical energy? How much of this is using stored energy?
  • Do you know of any hydroelectric reservoirs in your area? 
  • Do you think you use the same amount of electrical energy each day? Explain.
Connecting and Relating
  • How much of your day-to-day living involves the use of electrical energy? How much of this is using stored energy?
  • Do you know of any hydroelectric reservoirs in your area? 
  • Do you think you use the same amount of electrical energy each day? Explain.
Relating Science and Technology to Society and the Environment
  • What impact would you experience if energy could not be stored, and there was a limit on how much electrical energy you could use per day? Explain.
  • Does our ability to store energy impact the need for energy conservation? Explain.
  • What would happen if there was not enough electrical energy created to meet society’s demands? Explain.
  • The development and storage of electrical energy often involves the construction of infrastructure, land development, deforestation, etc. What issues need to be explored before such development occurs?
Relating Science and Technology to Society and the Environment
  • What impact would you experience if energy could not be stored, and there was a limit on how much electrical energy you could use per day? Explain.
  • Does our ability to store energy impact the need for energy conservation? Explain.
  • What would happen if there was not enough electrical energy created to meet society’s demands? Explain.
  • The development and storage of electrical energy often involves the construction of infrastructure, land development, deforestation, etc. What issues need to be explored before such development occurs?
Exploring Concepts
  • Think about an electrical device you use on a daily basis. How does this device get energy? Does it have the capacity to store energy? How?  
  • How can stored energy make an electrical system more sustainable? 
  • Describe the energy conversions that are taking place in each of the following energy storage technologies: battery, flywheel, and pumped hydroelectric energy.
  • How do the people running an electricity generating plant know when to increase the amount of electricity they are sending out and when to reduce the amount sent out into the grid?
Exploring Concepts
  • Think about an electrical device you use on a daily basis. How does this device get energy? Does it have the capacity to store energy? How?  
  • How can stored energy make an electrical system more sustainable? 
  • Describe the energy conversions that are taking place in each of the following energy storage technologies: battery, flywheel, and pumped hydroelectric energy.
  • How do the people running an electricity generating plant know when to increase the amount of electricity they are sending out and when to reduce the amount sent out into the grid?
Teaching Suggestions
  • This article can be used to support teaching and learning of Physics, Electricity and Alternative Energy related to energy storage, electricity generation, energy sources, potential & kinetic energy and energy transformations. Concepts introduced include energy storage technologies, electrode, electrolyte, flywheel, inertia, turbine and reservoir.
  • To introduce this topic, teachers could ask students whether they use the same amount of energy each day. Students could form partners or groups to discuss why their energy usage may vary from day to day.
  • To consolidate learning after reading the article and viewing the embedded videos, teachers could have students complete a Concept Definition Web learning strategy for the concept of energy storage technologies. Ready-to-use Concept Definition Web reproducibles are available in [Google doc] and [PDF] formats.
  • To consolidate learning, teachers could have students create a graphic organizer or infographic that outlines the transmission of electricity from source to users, including the energy storage options. For support with teaching and learning about making infographics, refer to the Infographics Creator learning strategy. 
  • To further consolidate learning of this topic, teachers could have students complete an Exit Slip. A ready-to-use reproducible for this learning strategy is available to download in [Google doc] and [PDF] formats.
Teaching Suggestions
  • This article can be used to support teaching and learning of Physics, Electricity and Alternative Energy related to energy storage, electricity generation, energy sources, potential & kinetic energy and energy transformations. Concepts introduced include energy storage technologies, electrode, electrolyte, flywheel, inertia, turbine and reservoir.
  • To introduce this topic, teachers could ask students whether they use the same amount of energy each day. Students could form partners or groups to discuss why their energy usage may vary from day to day.
  • To consolidate learning after reading the article and viewing the embedded videos, teachers could have students complete a Concept Definition Web learning strategy for the concept of energy storage technologies. Ready-to-use Concept Definition Web reproducibles are available in [Google doc] and [PDF] formats.
  • To consolidate learning, teachers could have students create a graphic organizer or infographic that outlines the transmission of electricity from source to users, including the energy storage options. For support with teaching and learning about making infographics, refer to the Infographics Creator learning strategy. 
  • To further consolidate learning of this topic, teachers could have students complete an Exit Slip. A ready-to-use reproducible for this learning strategy is available to download in [Google doc] and [PDF] formats.

Learn more

Wind Turbine Energy Storage (2017)

This video (1:25 min.) from DOB-Academy Studio gives a brief overview of the way energy generated by wind turbines can be stored for use at times when wind energy is not being generated.

Why Will Energy Storage Lead the Way to a Clean Energy Future? (2018)

Infographic from Saft summarizing energy demand and how energy storage could help facilitate the shift from non-renewable to renewable energy resources for energy generation.

Can 100% Renewable Energy Power the World? (2017)

This TED-Ed video (5:54 min.) discusses the possibility of moving entirely to reusable resources to provide global energy.

References

Energy Storage Association. (n.d.). Energy storage technologies.

National Energy Board. (2019, June 17). Chapter 4. Technology case results.

World Nuclear Association. (2019, May). Electricity and energy storage.