Lesson video

Welcome to today's lesson on power stations.

It's part of the unit: Fuels and Energetics.

My name's Mrs. Mytum-Smithson, and today we're going to look at how burning fuels can be used to generate electricity.

Don't worry if you don't know much about this, 'cause we're going to go through it step by step.

By the end of the this lesson, you should be able to describe how burning fuels can be used to generate electricity.

The key words for today's lesson are fuel, turbine, pollutant, non-renewable energy resource, greenhouse gas.

On the next slide, there's some sentences that include this, so press pause, have a read, and then press play when you're ready to start the lesson.

Today's lesson on power station consists of two learning cycles.

Firstly, we're going to learn about power stations, and then we're going to move on to evaluating power stations.

So let's get learning with our first learning cycle power stations.

Power stations can be found in many parts of the UK.

Maybe you've got one near you or you've driven past one.

They look a little bit like this.

They burn fuels to generate electricity, and that electricity powers homes, electric vehicles, and industry.

Fuels release energy when burned.

And historically, fossil fuels have been used in power stations.

Fossil fuels are formed from the dead remains of organisms over millions of years, and they are coal, crude oil, and natural gas.

Here's a picture of coal, if you don't know what it looks like.

Now, some power stations are fueled by alternative fuels.

And so these are things like wood pellets, and these can also be used in the power stations to generate electricity.

In power stations, the burning of fuels heats water, and this generates steam.

And the steam is at high pressure, and that can turn massive turbines at high speed.

So here's a picture of a massive turbine, and these can be around eight metres in diameter.

So if you stood about four or five people on top of each other, that would be the diameters, so from top to bottom, of these big turbines.

Those spinning turbines turn the electrical generators, and those electrical generators produce the electricity that we use.

A quick check for understanding now.

Which statement best describes the use of fuel in a power station? Is it to heat water into steam, is it to heat the turbine to generate electricity, or is it to heat the generator to generate electricity? Pause the video now to have a think, and then press play, and we'll tell you the answer.

So well done if you said the use of fuel in a power station, that is used for heating water into steam.

So if you said A, you're absolutely correct.

Well done.

How do the turbines move? Is it low-pressure seam turns the turbine, high-pressure steam turns the turbine, high-pressure water turns the turbine? Pause the video, have a think, press play when you've got your answer.

Well done if you said it's high-pressure steam that turns the turbine.

You've done really well if you've got that one right.

What I'd like you to do for this check for understanding is select all the true statements.

So there might be one, there might be more than one.

The turbines generate electricity, the generators generate electricity, electricity is needed to turn the turbines, turbines turn the generators.

Pause the video and have a think, select your answer or answers, then press play, and I'll tell you if you're right or not.

Well done for completing that task.

Let's see how you got on.

So well done if you said the generators generate electricity, and the turbines turn those generators.

Well done.

What I want you to do now for task A is I want you to put the statements in order to describe what happens in a power station.

So I've got six statements for you, and you're going to put them in order for what happens in a power station.

So we've got water changes to steam, generator generates electricity, high-pressure steam turns a turbine, spinning turbine turns the generator, electricity is distributed to houses, shops, and factories, fuel heats water.

Pause the video, put these statements in order, and press play, and we'll go through the answers together.

Well done, then, for completing task A.

Let's see if you've got the statements in the right order.

So the first thing that happens is the fuel heats the water.

The water then changes to steam, high-pressure steam then turns the turbine, and that spinning turbine turns the generator.

The generator generates electricity.

And finally, the electricity is distributed to houses, shops, and factories.

So well done if you've got all of those correct, we've completed our first learning cycle about power stations.

Now we're going to look at evaluating power stations.

Fossil fuels are non-renewable energy resources that are burnt in some power stations.

Burning these fuels produces pollutants, and these pollutants have got an impact on the environment, so on the world around us.

So carbon dioxide gas is a greenhouse gas that can contribute to global warming.

Sulphur dioxide gas, nitrogen oxide gases, and carbon particulates.

These pollutants are mostly colourless gases that cannot be seen with the human eye.

Now, a non-renewable resource is something that cannot be replaced in our lifetime once they are used up.

So in the case of fossil fuels, it's coal, natural gas, or crude oil.

And power stations are now moving away from fossil fuels to use alternative fuels such as wood pellets.

And these are due to the pollutants that are produced when burning these fossil fuels.

So here's the wood pellets, and these are an alternative to using coal, oil, and natural gas.

There are advantages and disadvantages to burning fossil fuels in a power station.

So you can release large quantities of energy quickly when burned in power stations.

So when you need more energy, so when you need more electricity, for example, in winter when everybody gets home from work and they're turning their heating on and they're turning their kettles on, we're going to need more electricity.

And that's easy to do because you can burn some fossil fuels.

and they're going to release that energy quickly.

It's very easy to control.

And also, the supplies at the moment are relatively easy to access.

So at the moment, it's quite easy to say, "We need some more coal.

Let's get some more coal." However, they are non-renewable, and global supplies, so that supplies across the world, are running out, and they can also cause harm to both organisms and the environment.

So the pollutants, or the gases and the particulates, they're gonna cause harm to organisms, that's living things, and the environment.

A quick check for understanding now.

Which option or options is an advantage or are our advantages of using fossil fuels in a power station? Is it production of harmful pollutants, non-renewable, so global supplies of fuel are running out, can release large quantities of energy when burned in power stations, relatively easy to access current supplies? So we're looking for advantages of using fossil fuels in a power station.

Select your answer or answers, and then press play when you're ready.

Well done if you said that they can release large quantities of energy when burned in a power station, that's definitely an advantage.

And they're also relatively easy to access current supplies.

The two other ones, production of harmful pollutants, that's a disadvantage to using fossil fuels in a power station.

And they're non-renewable, so they're running out across the world.

That is also a disadvantage.

So well done if you've got those two advantages correct.

The products formed when fossil fuels are burned can cause health and environmental problems. So one example of this is global warming occurring due to the increase of greenhouse gases in the atmosphere, such as carbon dioxide.

And here's a table that sums it up.

So we've got some things that are produced from burning fossil fuels.

So we've got carbon dioxide, sulphur dioxide, nitrogen oxides, and carbon particulates.

They're all produced when you burn fossil fuels.

Issue with carbon dioxide is that it increases those greenhouse gases, and that could lead to or contribute to global warming and climate change.

We've got sulphur dioxide.

Now that gas, when it's in the atmosphere, it reacts with water in the air, and that can form an acid, and that gives us acid rain, and also some breathing difficulties for some people.

Nitrogen oxides can react with water in the air to also form an acid, and that also contributes to acid rain.

We've got carbon particulates, they form soot in the air.

So that's small particles of carbon causing smog, and that can lead to global dimming.

So this is where the views in some cities are darker than they need to be, and it can also cause breathing difficulties.

So if you look at some busy cities across the world, you can see lots of and lots of smog, lots of visual pollution caused by these carbon particulates.

And you can see that there are health implications, such as breathing difficulties, caused by the pollution in the air.

Here's a quick check for understanding.

Which substance causes global dimming? Is it sulphur dioxide, carbon dioxide, carbon particulates, or nitrogen oxides? Pause the video now, select your answer, and then press play, and I'll let you know if you're right.

Well done for completing that check for understanding.

If you said carbon particulates cause global dimming, you're absolutely right, so well done.

I've got a true or false for you now.

Coal is a non-renewable energy resource and can be replaced in our lifetime.

Is that true or is that false? Read the statement again, pause the video for some thinking time, and then when you come back, I'll let you know if you're right or not.

Well done if you said that that statement was false.

Now I want you to justify your answer.

So we've got coal, natural gas, and oil may take many millions of years to be formed so it cannot be replaced in our lifetime.

Or coal, natural gas, and oil are renewable fuels that can be made quickly.

Pause the video now, decide on what you're going to select, and then press play, and I'll give you the answer.

Well done if you said that coal, natural gas, and oil take many millions of years to be formed, so cannot be replaced in our lifetime.

That is why coal, natural gas, and oil are called non-renewable energy resources.

Now what I'd like you to do is have a little look at those two images.

So we've got City A and City B, and I'd just like you to think about what's different about the images of the cities below.

In a second, I'm gonna put up a different slide, and that's got some questions for you on it.

So just have a look at these images for now.

Pause the video and have a look at the images, then press play, and I'll let you know the questions.

The pupils are discussing cities A and B.

Andeep said, "Some air pollution is invisible, so the air in City B could be polluted." Jun says, "City B may be polluted.

You can't tell from a photograph." Alex says, "City B does not have polluted air 'cause the air looks clean." And Jacob said, "The air in City B is colourless, so it cannot be polluted." So colourless just means it has no colour.

So who do you agree with? You can agree with more than one person, so pause the video while you decide and then press play, and I'll tell you the answer or answers.

Well done if you agree with Jun and Andeep.

City B might be polluted.

You can't tell from a photograph because of Andeep's reason, which is some air pollution is invisible.

So the air in City B could be polluted, and you just can't tell.

Jacob was incorrect because he said that the air in City B is colourless, so it cannot be polluted.

And Alex said, "City B does not have polluted air because the air looks clean." So he was also wrong.

Well done if you got those right.

Now, what I'd like you to do for task B, part one, is match up the product from burning fossil fuels to the issues it can cause.

A product might have more than one issue.

So here's the list of products produced, sulphur dioxide, carbon dioxide, carbon particulates, nitrogen oxides.

And here's their issues, greenhouse gas, global warming, global dimming, health problems, acid rain.

Pause the video while you decide, and then press play, and we'll go through the answers together.

Well done for working hard and completing part one of task B.

Let's go through the answers now.

So sulphur dioxide can cause health problems. It can also cause acid rain.

Carbon dioxide is a greenhouse gas and can cause global warming.

Carbon particulates can cause global dimming and also some health problems. Nitrogen oxide, that's going to cause acid rain, so that can contribute to acid rain.

So well done if you've got all of those correct.

You're doing really well.

What I'd like you to do now for part two of task B, it's got two parts, it's got part A, which is complete the table to state both the advantages and disadvantages of the use of fossil fuels in power stations.

And part B is I want you to complete the following sentence to state your opinion about the use of fossil fuels in power station.

So you can agree or you can disagree.

It's up to you.

I think that fossil fuels should or should not be used in power stations because.

So I want you to choose should they be used or should they not be used, and give me a reason.

Pause the video while you complete this part of the task, then press play, and we'll go through the answers together.

Well done for completing this task.

Let's have a look at our answers.

So your answers might include, advantages being fossil fuels can release large quantities of energy and fossil fuels are relatively easy to obtain.

The disadvantages, so we've got health and environmental issues.

For example, carbon dioxide contributes to global warming.

Acid rain is produced by both sulphur dioxide and nitrogen oxides dissolving in the water in the air.

Global dimming and health problems are caused by carbon particulates, and fossil fuels are going to run out because they are a non-renewable energy resource, which means that they're not going to be made again within our lifetime.

So we need to find some alternatives to replace these fossil fuels.

Now let's have a look at your opinion.

So your answers might include, for using fossil fuels, so if you said that we should use fossil fuels, you could have argued that they produce large quantities of energy and are relatively easy to obtain.

And against fossil fuels, so if you said that we should not use 'em in power stations, you might have said that they produce lots of different pollutants which are harmful to organisms, so that's living things, and the environment, and they're also non-renewable, so we'll run out.

Well done if you've completed that and done that correctly.

Here's a summary for today's lesson on power stations.

Non-renewable energy resources cannot be replaced in our lifetime once they are used up.

A fuel can be burned to change water into steam.

Steam generated in power stations is at high pressure and turns massive turbines at high speed.

Spinning turbines in power stations turns electrical generators that generate electricity.

Burning coal, oil, or gas in a power station makes carbon dioxide gas and other pollutants.

Well done for working really hard this lesson.

I'm sure that you're much more knowledgeable now about fossil fuels and power stations and how electricity is generated using fuels.

Well done for working really hard this lesson.