Lesson video

Hello, my name is Mrs. Mehrin, and I'm so excited to be learning all about the Sun as an energy source with you.

Let's begin.

Welcome to today's lesson from the unit, climate change and sustainability.

Your learning outcome is, "I can describe how solar cells use the Sun as a renewable energy source to generate electricity." Now, I know that learning can sometimes be a little bit challenging, but that's okay, because it just means that we are going to learn together and we are going to work really hard and learn some fabulous new things.

Let's begin.

So, here are your five keywords for today's lesson.

Alongside these five keywords are the definitions.

Now, I am going to be referring to these definitions throughout today's lesson.

However, if you find it helpful to have these written down, you can pop the video on pause here and have a go at doing that.

Off you go.

Fantastic.

Well done.

Now, our lesson is split into two parts.

Let's begin with the first one, energy from the Sun.

Now John has a new calculator.

He notices there is a dark rectangular window above the calculator display.

Just there in the picture, and it's got a purple rectangle around it.

So Jun says, "My teacher explained my calculator has solar cells, but I don't know what these are." Do you know? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

Now, Jun says, "I have heard of the word solar before.

I know that this means relating to the Sun." And Sofia says, "Yes, the solar system is made up of the Sun and everything that orbits around it." Now, do you know any other words with solar in them? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

So you might have been thinking of words like solarium, or words that you might have seen on sun cream, for example, sometimes have the word solar on them.

You might have heard of solar panels as well.

So lots of things that you might have seen the word solar coming up.

So, Jun says, "I remember using cells when we built electric circuits.

A cell is a single unit that is needed for electricity to flow around a circuit." And Jun's teacher says, "That's right, so solar cell is a single unit that is used to convert light from the Sun into electricity." Now, the window on Jun's calculator is a solar panel made up of solar cells.

So when light from the Sun hits the layers of material inside each solar cell, the light is converted into a flow of electricity that can power a small electrical device such as a calculator or a watch.

Now, let's do a quick check-in of your learning before we continue.

What is a solar panel? Is it A, one large solar cell, B, a collection of many solar cells, or C, rays of light produced by the Sun? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answer is a collection of many solar cells.

Well done.

Now, Jun says, "If I left my calculator in my pencil case all day, would it go off because light has not been able to reach the solar cells to generate electricity?" Well, so long as there is enough light, a solar-powered device can work using energy from the Sun without needing any batteries.

And most solar-powered calculators also have a small battery inside, which helps the calculator work in places where there's not enough light, like in a dark room.

So, true or false? Each solar cell converts heat from the Sun into electricity.

Is that true or false? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answer is false.

Now, each solar cell converts light from the Sun into electricity.

Now, Jun says, "The lights in our garden have solar panels too." And Sofia says, "How do they generate electricity at night when there is no light from the Sun?" Do you have any ideas? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

So some garden lights use solar panels to absorb energy from the Sun during the day.

The panels contain solar cells that convert light from the Sun into electricity, and store it in rechargeable batteries.

And when it gets dark, the lights have built-in sensors that detect the low light levels and turn on the lights.

Now, Jun says, "Using solar power means that we do not have to rely on mains electricity that is often generated in a power station by burning fossil fuels." Now, why do you think this might be important? Have a think back to some of your previous learning.

Why do you think that this is important? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

Well, Sofia says, "Fossil fuels are a non-renewable energy source, which means they cannot be replaced once they are used up.

This is a problem because one day, they will eventually run out." Now, Jun says, "Is generating electricity using light from the Sun, an example of a non-renewable energy source too?" What do you think? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

And Sofia says, "No, the Sun is a renewable energy source because it will always be there to provide energy and it won't run out." Now, using light from the Sun to generate electricity is an example of what? Is it A, a renewable energy source, B, a non-renewable energy source, or C, global warming? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answer is A, a renewable energy source.

Now here is your first activity.

It says, "Look around your home or school for devices with solar panels that convert light from the Sun into electricity.

Make a list or take photographs of what you find, and try to explain to a partner how these devices work without using mains electricity." So I'll give you some time now.

I'd like you to pause the video here and have a go at doing this activity.

Off you go.

Fantastic.

Well done.

So, a power bank is a great one, because a lot of power banks nowadays have solar panels attached to them so that if for example, your phone's battery dies and it runs out, then you can use these solar panel power banks to charge up your mobile phone.

Also, an alarm clock is another great one as well.

So this power bank and alarm clock both have solar panels containing many solar cells, and each cell converts light from the Sun into electricity.

Now we are onto the second part of our learning today, which is solar power in our homes.

Let's begin.

So Jun says, "Do we only use the Sun as an energy source for small appliances like calculators and lights?" What do you think? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

Sofia says, "No, many households use solar power to generate electricity for their entire home." So solar panels full of solar cells are often fitted onto roofs of buildings such as houses and schools to generate electricity using renewable energy sources.

The carbon footprint of solar panels is quite small compared to generating electricity by burning fossil fuels, as they last over 25 years and the materials used in the panels can be recycled.

Now, the electricity that is generated by the solar panels travel through wires and cables into the building's electrical system.

And this electricity can be used to power lights and other electrical appliances.

Now, Jun says, "Can electricity be generated using solar panels on a cloudy day?" What do you think? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

Well, the solar engineer says, "Yes, using light from the Sun as an energy source only requires some level of light.

However, solar panels are less effective when it's cloudy." In the UK, most solar panels face south to receive the most light from the Sun throughout the day.

Now, Jun says, "If my home has solar panels, can the solar cells generate electricity at night?" What do you think? Again, I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

Well, the solar engineer says, "If you have solar panels and use electricity at night, you will need to access power from the National Grid or a battery storage system, not the solar panel." Now, true or false? Solar panels only work if they are facing south.

Is that true or false? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answer is false.

And the reason for that is because solar panels work when facing in any direction.

In the UK, most solar panels face south to receive the most light from the Sun throughout the day.

Now, Jun says, "My home does not have solar panels.

How can my family use electricity generated using light from the Sun?" Sofia says, "I heard that more people are getting their electricity from solar farms, but I don't know what these are." Do you have any ideas? I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

Well, a solar farm is a large area of land that can be covered with thousands of solar panels to generate as much electricity as possible.

And the electricity produced by a solar farm is sent to the National Grid, which distributes it to homes, businesses, and other buildings in the area.

Now let's do a quick check-in of your learning so far, and it says, "When land is covered in thousands of solar panels to generate large amounts of electricity, this is called a what?" A, a solar garden, B, a solar park, or C, a solar farm? Again, I'll give you five seconds to think about your answer.

Off you go.

Fantastic.

Well done.

The answer is C, a solar farm.

Now, here is Task B.

It says, "Explain to a partner why many solar panels in the UK face in the same direction, which is usually south." I'll give you some time now.

I'd like you to pause the video here, and have a go at doing that.

Off you go.

Fantastic.

Well done.

So, I think most solar panels in the UK face south because the Sun rises in the east and sets in the west.

So the south facing side of a house receives the most light from the Sun during the day.

This means the solar panels can generate the most electricity, making them more efficient.

Now, the second part of your activity says, "Jun wants to persuade his family to get solar panels on the roof of their house.

Work with a partner to make a list of reasons, for and against, using solar panels to generate electricity." So, again, I'm gonna give you some time to do this activity.

So I'd like you to pause the video here, and have a go at doing this.

Off you go.

Fantastic.

Well done.

So, reasons for.

The Sun is a renewable energy source.

Using solar power to generate electricity does not create harmful greenhouse gases.

Solar power is free to use.

Solar panels last around 25 years and can be recycled.

Now, reasons against.

Solar panels can cost a lot of money.

Less electricity is generated on cloudy days.

Electricity is not generated at night.

It may need battery storage system as well as solar panels.

Now we are onto the summary of your learning today.

A solar panel is a collection of many solar cells, which converts light from the Sun into electricity.

Electricity generated using solar panels is renewable, as the Sun will always be there as an energy source.

Solar panels can be fitted onto houses and schools to generate electricity using renewable energy sources.

And a solar farm can generate electricity for thousands of homes.

Now you have worked so hard today.

I'm so proud of your fantastic work and your amazing critical thinking.

Well done.