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More people are looking (not literally) at as a sustainable energy solution. In fact, in the US, the use of solar power has increased more than in K-12 schools in the last 10 years, with one in nine students attending a school powered by solar energy.

Solar power is harnessed from the sun’s light and heat. Solar panels absorb sunlight and generate electricity, which is converted to be used in homes, businesses, and schools. The process produces little to no greenhouse gases and can take place wherever there’s sun. Solar thermal systems are another way to use solar power, by using the sun’s heat to warm water or air.

Teaching students how solar power works can emphasise the importance of renewable energy and sustainability, and prepare your students for a future where we no longer rely on fossil fuels.

Here are four STEM activities you can do with your students to help them build a practical understanding of solar energy.

Create a sundial

Sundials have been used throughout history to tell the time by tracking the sun’s shadow. While we might have clocks now, creating a sundial is a great way to get students thinking about the utility of the sun in everyday life.

To do this activity, you’ll need:

• A paper plate or sturdy cardboard
• A pencil, stick, or dowel (for the gnomon)
• Modelling clay or a small blob of playdough
• A ruler
• Markers or pens
• A compass or phone with a compass app
• Access to an outdoor area with direct sunlight

Start the activity by explaining to your students how sundials have been used in the past and how they use the sun’s shadow to tell the time. Then, give each student a paper plate or piece of cardboard. This will be the base of their sundial.

Have students use a ruler to draw a line from the centre of the plate to the outside, marking the 12 o’clock position. They can add additional lines for other hours later on. Then, they should push the pencil, stick, or dowel through the centre of the plate and secure it underneath with the modelling clay so it stands upright, acting as the gnomon.

Now, take them outside to a sunny spot. Students should orient the gnomon to true north using the compass and mark the shadow of the gnomon at each hour throughout the day. And there you have it – they’ve created their own sundial!

Run a water purification experiment

Another way you can showcase the power of the sun is by using it to purify water through evaporation and condensation. This science experiment actually mimics solar desalination systems (removing salt) used in real-world water purification!

You’ll need the following:

• Large bowl
• Small cup or glass
• Small stone
• Cling film
• Rubber band
• Saltwater or muddy water

Working together in small groups, students first put the saltwater or dirty water into the large bowl and then place the small cup upright in the centre of the bowl without letting any water in. They should then cover the bowl with the cling film and secure it with a rubber band.

Next, they should put a small stone in the centre of the cling film to create a dip over the cup and leave it in the sun for a few hours. The sun heats the water, causing it to evaporate and gather on the cling film, and then drip into the cup as clean water.

Students can then compare the dirty or salty water with the purified water, through observation or even using a microscope. You might even finish the activity by showing them videos of industrial-scale solar desalination systems – and explain how they just made their own version!

Install solar-powered devices

There are many everyday items that you use in school that can be powered by solar energy, giving students a small-scale example of solar power in action. You can use a solar-powered charger to charge laptops or tablets or solar-rechargeable batteries to power torches or calculators.

Taking it a step further, you could ask students to use small solar panels to power a fan. Using mini solar panels, a small direct current (DC) motor, a propeller, wires, and tape, students can create their own solar panel project that mimics real-life applications.

To make the fan, they should first connect the solar panel to the DC motor, using the solar panel’s positive (+) and negative (-) ends to the matching motor wires. Then, they gently push the fan blade onto the motor’s spinning rod, using some tape or glue to keep it in place.

Ask students to take the fan outside or near a sunny window and watch their reaction as the blade starts spinning! You can also get them to cover the panel with their hands, so they can see that it only works when the panel gets sunlight.

Ask students to reflect on what it would mean if the whole school’s electricity came from solar power and what the benefits and limitations of using solar energy are in different contexts. For example, solar chargers are great if you’re in a remote area without electricity, but not so useful during the night or in cloudy places.

Visit places with solar panels

A final way to help your students learn about solar energy is to take them to a place with solar panels. Maybe your school already has a solar panel roof, or if not, you could take a trip somewhere to show students the concept in action.

If there is a solar farm nearby, you could take them there to see how sunlight is turned into energy on a large scale and can power entire communities. They could even learn about careers in renewable energy from the people who work there.

There might also be a solar-powered greenhouse or urban farm in your school area that uses solar energy to power fans, water pumps, or heating systems. This would be a great opportunity to combine two aspects of environmentally-friendly living – solar power and sustainable farming.

You could look up local solar-powered water treatment plants, too. Try to visit after the water purification classroom experiment, so students can see how solar energy powers water pumps and filtration systems.

Powering a brighter future with solar

There’s no doubt that solar power is going to be a huge part of our energy future. By bringing the topic into your classes now, students can understand the abundant value of the sun and be inspired by renewable energy solutions. Who knows – maybe you have some future solar energy scientists in your group!

Further reading

Discover more ways to connect and care for the environment from your classroom. Read How to use the UN Sustainable Development Goals in the classroom, Environmental Systems and Societies: A new beginning, and How to put climate change at the heart of education.

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