# Sunshine City – A Lesson Plan on Renewable Energy

Normally we don’t share super formal lesson plans on Layers of Learning, but when the Lego Company asked for lesson plans about renewable energy for their LegoSmart contest last year, we were happy to submit ours!  Guess what!  We won!  Here’s the complete Sunshine City Lesson Plan we created that won the \$1,000 Grand Prize.  Click on the link or on any of the pages below to get the printable version of the lesson plan.

Read on for the basics of this very fun lesson plan that involves solar power and Lego building blocks.

## The First Law of Thermodynamics

A discussion about energy can be best introduced by learning about the first law of thermodynamics.  Set up a row of dominoes and then knock them down using a chain reaction.  Discuss how the potential energy of the dominoes was released as the potential was turned into kinetic energy that actually knocked down the row. Potential energy is waiting to happen.  Kinetic energy is energy in motion.

What are some ways that energy is converted? (the sun gives plants energy, food gives our bodies energy, fuel gives cars energy, batteries give toys energy) We need to find ways to convert energy into energy we can use to power our cars, homes, and cities.

Unfortunately, non-renewable resources are not the answer.  We use many different sources of energy to power our machines on the earth, but most of our energy comes from fossil fuels like oil, coal, and gas.  These were formed millions of years ago and can’t be immediately replaced.  We are using them up really fast, so within the next century or so we may use them all up if we don’t find other energy sources.  An energy source that we can use up and run out of is called non-renewable, because we can’t just make more of it.

Most of our energy comes from the sun, but we don’t have efficient enough ways to collect and use it well.  Have students create a diagram that shows energy transfer, drawing along as the teacher describes where the energy from the sun can go.  Most of our energy begins with the sun.  It shines down on the earth.  Plants capture some of this energy and use it to make food.  We eat the food and can use the energy from that.

Older kids can also learn the rest of this cycle:  Over time the plant and animal remains are changed into coal or oil, but this takes millions of years.  These fossil fuels have chemical energy that can be changed into heat energy when they are burned in a power station.  Some of the heat energy rises back up into space and the cycle continues.

What if we could take in some of the sun’s energy that the plants aren’t using and turn it into electrical power?

Would that kind of energy be renewable or non-renewable? (renewable, because we can always get more)

What could we power with energy from the sun? (cars, lights, televisions, houses, schools, cities!)

The best part is that WE CAN use the energy from the sun!

## How does solar energy work?

First, we have to collect the energy. This is done with solar cells called photovoltaics (photo means “light” and voltaics means “electricity” because they convert light into electricity.)  Inside the solar cell there is a dark metal plate that collects the sun’s heat.  Air or water flows through a tube under that plate, and the tube gets hot.  When light hits the solar cells, electrical charges move through the layers of the plate and make an electrical current.  That electricity can power the things we need.

Demonstrate this concept with a solar powered calculator. If the solar panel is blocked, the light can’t get through and the calculator will not turn on.  The problem with only using solar power is that the solar cells and equipment needed to convert enough energy can be expensive.  In the long run though, solar energy SAVES money because we don’t have to keep paying for it.  There also isn’t enough sunlight in every place on earth to depend on it for energy by itself (the solar calculator wouldn’t work well on a cloudy day in Alaska), but it has the potential to be better distributed and also used together with other renewable resources in the future.

## Sunshine City

Give kids some Lego building blocks and an outdoor solar powered light.  Start by taking apart the light and examining the solar cell that collects the sun’s energy and then powers the light even after the sun has gone down (the energy is stored within a battery in the light). Challenge the kids to build Lego buildings using the solar panels from the solar powered light in the roof.  Their building will rely on the energy from the sun. Put all of your buildings together to make a city – Sunshine City.

Long after the sun goes down, Sunshine City is still alight from solar power.

## Discussion Questions:

• What does the first law of thermodynamics say?
• Name some non-renewable resources. What does non-renewable mean? Why do we use non-renewable resources?
• Name some renewable resources.  What does renewable mean?
• Why don’t we use more renewable resources?
• What are the problems with using solar power?
• How could those problems be overcome?

• Examine a specific city within the United States and determine whether or not its electrical needs could be met through solar energy.
• Research the cost of installing solar panels on your home.  Find out what happens in your city if the solar panels from your house collect more energy than your home needs.  Does the city pay you?  Does your state offer any incentives or rebates if you use solar power?
• Solar farms are becoming more common in the United States and around the world.  Some scientists are examining the potential of putting solar powered stations in space where there isn’t cloud cover and the sunlight is much stronger.  What are the benefits and drawbacks of space solar farms?
• Challenge kids to cook a hot dog using solar power.  What can be used to concentrate the power?  If they are successful, challenge them to boil water using solar power. (Hint: Foil works, but mirrors work even better!)
• Build a tabletop greenhouse and conduct experiments to see the difference between plants grown inside and outside of the greenhouse.
• Besides solar power, what other renewable energy sources could be scientifically pursued?

### 2 Responses to Sunshine City – A Lesson Plan on Renewable Energy

1. Shannon says:

What a fantastic lesson! I can see why you won! What is the youngest age group you try this activity with? I have a grade 2 class… Any warnings re: handling the photo cells? Thanks so much for sharing!

• I’m positive 2nd graders could handle this. Honestly, building the Legos is the toughest part. You don’t need to worry about the solar panels. They aren’t harmful and can be handled freely. Best of luck!