0:00:27 > 0:00:30Hello, children, what are you doing?
0:00:30 > 0:00:33We're cleaning our paintbrushes.
0:00:33 > 0:00:36Good thing you have a sink in your classroom.
0:00:36 > 0:00:38Do you know what happens when you send dirty water down the plughole?
0:00:38 > 0:00:41Does it go down the drain and underground?
0:00:41 > 0:00:43Yes! That's right.
0:00:44 > 0:00:49All your dirty water from the sink, bath and toilet all go down pipes
0:00:49 > 0:00:53and end up in the same place - underground, into the sewer.
0:00:55 > 0:00:59- Would you like to see where the dirty water goes?- BOTH: Yes, please!
0:00:59 > 0:01:02My friend Stewart is waiting to show you round.
0:01:02 > 0:01:04Off you go,
0:01:04 > 0:01:05down the drain.
0:01:08 > 0:01:11- Hello.- Hello. I'm going to take you down to my sewers.
0:01:11 > 0:01:14- Would you like to come with me? - BOTH: OK.
0:01:14 > 0:01:17- We'll open the door first.- Wow!
0:01:17 > 0:01:18Rather deep, isn't it?
0:01:18 > 0:01:20Yes. How deep is it?
0:01:20 > 0:01:23- It's as deep as two double-decker buses.- BOTH: Wow!
0:01:23 > 0:01:26That's quite deep.
0:01:26 > 0:01:27What's down there?
0:01:27 > 0:01:29Dirty water, sewage.
0:01:29 > 0:01:32- Ugh!- It comes from your toilet when you flush.
0:01:32 > 0:01:34- Can we go down there? - Of course you can.
0:01:34 > 0:01:37- Do you want to go down there with me?- BOTH: Yes.- OK, then.
0:01:37 > 0:01:40What we need is a helmet and gloves. Put this on your head for me.
0:01:40 > 0:01:42I'm going to take you down into the sewers.
0:01:42 > 0:01:47Stewart is taking the children into the dark sewer.
0:01:47 > 0:01:50We should never go into an underground sewer
0:01:50 > 0:01:54without the adults who work there, because it would be very dangerous.
0:01:54 > 0:01:56Watch your step!
0:01:56 > 0:01:59Right, let's go and look at some sewerage. Come on.
0:02:01 > 0:02:05- Are you ready for an adventure?- Yes! - Let's go. Keep with me.- Yes, sir!
0:02:10 > 0:02:13You may not realise it, but under our feet,
0:02:13 > 0:02:17there are hundreds of miles of tunnels and they are very important.
0:02:22 > 0:02:23What is sewage?
0:02:23 > 0:02:27If you think of all the houses, everybody lives in a house,
0:02:27 > 0:02:30all the water goes down and collects in a big sewer system.
0:02:30 > 0:02:35So from every house, all their taps, all the toilets, the baths,
0:02:35 > 0:02:39the showers, it all comes down into the sewer system,
0:02:39 > 0:02:41and even from the roads. When it rains, it comes down the drains
0:02:41 > 0:02:45and then it comes into this great big sewer system.
0:02:45 > 0:02:48This is what takes your sewage away from the towns and your houses.
0:02:48 > 0:02:52From your toilets, these go into the drains.
0:02:52 > 0:02:53A pipe like this.
0:02:53 > 0:02:56This is a four-inch pipe, but they can get bigger.
0:02:56 > 0:03:00Six, nine inches, 12 inches, 18 inches, 24 inches,
0:03:00 > 0:03:04until you get a big eight-foot barrel, like this. A big sewer.
0:03:04 > 0:03:08The sewers work on a really important thing called gravity.
0:03:08 > 0:03:11Gravity makes water flow downhill.
0:03:11 > 0:03:12How does it travel?
0:03:12 > 0:03:16To make the sewer system work, all the pipes, they are not flat.
0:03:16 > 0:03:17They have a small gradient.
0:03:17 > 0:03:20They are slanted like that, to make the water run.
0:03:20 > 0:03:23If you have it flat like so, when we put the water in,
0:03:23 > 0:03:24nothing comes out the end.
0:03:24 > 0:03:27To make the water go, they tilt the pipe.
0:03:27 > 0:03:31That's how it flows down the drain, like that.
0:03:31 > 0:03:34That's how we take all your waste water away.
0:03:34 > 0:03:36- Can we go along the tunnel now? - Of course.
0:03:36 > 0:03:39- Are you ready? Have you got your torches on?- BOTH: Yes.
0:03:39 > 0:03:43OK, then, if you want to follow me. What we do is walk up here.
0:03:43 > 0:03:45There's a bit of poo there.
0:03:45 > 0:03:47This is a sewage tunnel.
0:03:47 > 0:03:50All our dirty water travels from your homes
0:03:50 > 0:03:52into these underground tunnels.
0:03:52 > 0:03:55This is real sewage.
0:03:55 > 0:03:58This is when you go to the toilet, you flush your chain
0:03:58 > 0:04:01and it comes down into the sewer system.
0:04:01 > 0:04:03- Eugh!- There's some toilet paper!
0:04:03 > 0:04:06That's all toilet paper, yes.
0:04:06 > 0:04:08That is so disgusting!
0:04:08 > 0:04:12- What do you think of that? - Er, poo.- Yuck.
0:04:12 > 0:04:15It smells quite yuck.
0:04:15 > 0:04:18You have to clean the sewer every day or every week?
0:04:18 > 0:04:22No, we clean this sewer every eight weeks.
0:04:22 > 0:04:25We have to get a lorry and special pipes
0:04:25 > 0:04:28and we go in there and suck up all the grit and dirt
0:04:28 > 0:04:32- and take it away.- That sounds quite yucky.- It is quite yucky.
0:04:32 > 0:04:36OK, children, now that you've seen how a sewer works,
0:04:36 > 0:04:40it's time to go back to the surface to see what happens next.
0:04:49 > 0:04:52Now it's time to visit the sewage treatment plant,
0:04:52 > 0:04:54where Ben will show you round.
0:04:55 > 0:04:57- Morning, children. - BOTH: Morning.
0:04:57 > 0:04:59This is a treatment works,
0:04:59 > 0:05:01where sewage comes after it's been through the tunnels.
0:05:01 > 0:05:04- Do you want to see how we clean and recycle it?- BOTH: Yes.
0:05:04 > 0:05:07Excellent. Follow me.
0:05:13 > 0:05:16This is the waste-water treatment works where all the sewage
0:05:16 > 0:05:19and waste water, comes to be treated.
0:05:19 > 0:05:21It looks like a big water monster!
0:05:21 > 0:05:24A big water monster!
0:05:24 > 0:05:28- Does it have wee in it? - It has got wee in it.- Poo?- Yes.
0:05:28 > 0:05:31Anything from the house is collected through the pipes,
0:05:31 > 0:05:33comes to the treatment works to be treated
0:05:33 > 0:05:35and this is what it looks like to start with.
0:05:35 > 0:05:37What we'll do is take samples as we go round
0:05:37 > 0:05:40and show you how it gets cleaner and cleaner.
0:05:40 > 0:05:43- Now, we'll go and see the next stage.- Yeah.- Yes.
0:05:43 > 0:05:45OK? Follow me.
0:05:45 > 0:05:48All the dirty water we saw in the sewers
0:05:48 > 0:05:51comes to a sewage-treatment plant, like this one,
0:05:51 > 0:05:53where they make it all clean again.
0:05:54 > 0:05:57The first process is like a sieve,
0:05:57 > 0:06:00to get rid of all the big bits of rubbish in the water.
0:06:00 > 0:06:01In this machine here,
0:06:01 > 0:06:05there is one of these screens for things like cotton buds.
0:06:05 > 0:06:08Anything flushed down the toilet that's too big to treat,
0:06:08 > 0:06:09this is where we take it out.
0:06:09 > 0:06:11Where do the big bits go?
0:06:11 > 0:06:16All the bits we take out here we can take to burn, to produce energy,
0:06:16 > 0:06:19or we can take to landfill sites.
0:06:20 > 0:06:21This way.
0:06:21 > 0:06:24Here we have the next stage of the cleaning process.
0:06:24 > 0:06:26This is what we call a settlement tank.
0:06:26 > 0:06:29Leaving the dirty water to settle in these tanks
0:06:29 > 0:06:33let's all the big bits sink to the bottom
0:06:33 > 0:06:35so they can be taken away.
0:06:35 > 0:06:39So, here, we have taken another sample from these tanks.
0:06:39 > 0:06:42Can you see in this one, can you see the sludge settling to the bottom?
0:06:42 > 0:06:44BOTH: Mm-hm.
0:06:44 > 0:06:46That's sludge we draw out of the bottom of the tank
0:06:46 > 0:06:48and this cleaner water we take off the top.
0:06:48 > 0:06:50What is sludge?
0:06:50 > 0:06:52Sludge is the poo that we've allowed to settle
0:06:52 > 0:06:53to the bottom of the tank.
0:06:53 > 0:06:58We then suck that out and take it away and use it to help feed plants.
0:06:58 > 0:07:01The water looks clean, but there's still tiny germs in it,
0:07:01 > 0:07:03so we need to take those out.
0:07:03 > 0:07:06I'll show you how we do that. Follow me.
0:07:10 > 0:07:14Here, this is the next stage of the treatment,
0:07:14 > 0:07:17or the cleaning, process. Although we've taken the solids out,
0:07:17 > 0:07:21there are still tiny germs that are in the waste water.
0:07:21 > 0:07:23What are germs?
0:07:23 > 0:07:26Germs are tiny, tiny bugs you can't see with your eyes.
0:07:26 > 0:07:31They are not good for us sometimes, so we need to take those germs out.
0:07:31 > 0:07:32We do that in these filter beds.
0:07:32 > 0:07:34The water is passed over the stones
0:07:34 > 0:07:37and the nice germs that live on these stones
0:07:37 > 0:07:41eat the bad germs, so that we get cleaner water off the bottom.
0:07:41 > 0:07:43Why do we need to clean sewage?
0:07:43 > 0:07:45We need to clean sewage to make sure it's safe.
0:07:45 > 0:07:47Because we don't want the nasty bugs
0:07:47 > 0:07:50getting into rivers, streams or the sea.
0:07:50 > 0:07:52We take out the bad germs, so we don't get ill.
0:07:53 > 0:07:56These germs here are called bacteria
0:07:56 > 0:07:58and they are really tiny.
0:07:58 > 0:08:00But not all germs are bad.
0:08:00 > 0:08:03Here, they use good germs,
0:08:03 > 0:08:05which attach themselves to these stones,
0:08:05 > 0:08:08to eat up the bad germs living in the dirty water.
0:08:08 > 0:08:12These special stones have lots of holes,
0:08:12 > 0:08:16so the good germs have somewhere to live and grow.
0:08:16 > 0:08:18So this is the very last thing we do
0:08:18 > 0:08:22and that is to check to make sure it's OK to put back into the stream.
0:08:24 > 0:08:28- And this is what it looks like when it goes into the stream.- Whoa!
0:08:28 > 0:08:32- That's really...wow. - Wow! That is so clear.
0:08:32 > 0:08:34See the difference?
0:08:34 > 0:08:38It's like you've just put the water in from the tap.
0:08:38 > 0:08:41Yes, that's not tap water, it's come from here.
0:08:41 > 0:08:44Now you know how sewage is cleaned and treated.
0:08:47 > 0:08:49Hello, children, you're back.
0:08:49 > 0:08:52What did you find out about where our sewage goes?
0:08:52 > 0:08:56All the dirty water goes down the pipes in our homes
0:08:56 > 0:08:59and then through big pipes underground, called sewers.
0:08:59 > 0:09:03We went down a manhole into a sewer.
0:09:03 > 0:09:06It was a big, dark tunnel where the sewage went.
0:09:06 > 0:09:09The sewage goes all the way to the sewage-treatment plant,
0:09:09 > 0:09:12where it's cleaned.
0:09:12 > 0:09:16First, all the bits of rubbish, like toilet paper, get taken out.
0:09:16 > 0:09:19The sewage is then sent to a tank,
0:09:19 > 0:09:21where the big bits sink to the bottom.
0:09:21 > 0:09:24These bits are called sludge.
0:09:24 > 0:09:28The sludge can be dried and used to make plants grow.
0:09:28 > 0:09:33Next, they have to clean the tiny bits you cannot see
0:09:33 > 0:09:34by using special stones.
0:09:34 > 0:09:39Then, the water is clean enough to go into the river.
0:09:39 > 0:09:41That's brilliant. Well done.
0:09:41 > 0:09:45Now we know what happens to our waste once it leaves our homes.
0:09:45 > 0:09:48Great work. Bye-bye.
0:09:48 > 0:09:51BOTH: Bye-bye, Curious Cat.
0:09:51 > 0:09:53Goodbye, children.
0:10:18 > 0:10:22Hello, children, what are you doing with those biscuit tins?
0:10:22 > 0:10:26- Hello, Curious Cat.- We're sorting out biscuit tins for our school project.
0:10:26 > 0:10:28Looks like you have plenty of tins there.
0:10:28 > 0:10:30But do you know how biscuit tins are made?
0:10:30 > 0:10:31No.
0:10:31 > 0:10:34Let's find out how it all begins.
0:10:38 > 0:10:40The tins are made of steel
0:10:40 > 0:10:45and steel is made from special rocks underground, called iron ore.
0:10:45 > 0:10:49Iron is a metal and it's found in rocks deep underground.
0:10:49 > 0:10:52To get to these rocks, we have to use explosives
0:10:52 > 0:10:56and big machines, to dig deep and take away the loose earth.
0:10:56 > 0:10:59The iron ore rocks are then loaded onto a truck
0:10:59 > 0:11:02and transported to the steel factory.
0:11:02 > 0:11:06To make steel, you need iron ore, coal and limestone,
0:11:06 > 0:11:08which all come from the earth.
0:11:09 > 0:11:12Are you curious to find out what happens next?
0:11:12 > 0:11:16- BOTH: Yes.- That would be great. - Then, off you go.
0:11:18 > 0:11:20To find out what happens next,
0:11:20 > 0:11:24you'll have to visit the steel plant, which is a huge factory
0:11:24 > 0:11:27where all the ingredients are brought together to make steel.
0:11:27 > 0:11:31My friend Chris is waiting to show you round.
0:11:37 > 0:11:38Hi, my name is Chris
0:11:38 > 0:11:41and I'm here to teach you all about our steel-making factory.
0:11:41 > 0:11:43All around you can see the raw materials for making steel -
0:11:43 > 0:11:47iron ore, coal and limestone.
0:11:47 > 0:11:49I'm glad you've already got your safety gear on.
0:11:49 > 0:11:53Now we're going to head to the blast furnace to see what we do next.
0:11:53 > 0:11:55Look at all the raw material!
0:11:55 > 0:12:00There is heaps here and it all comes from the earth.
0:12:02 > 0:12:04First, we need to mix the raw ingredients together -
0:12:04 > 0:12:07the iron ore, the coke and the limestone -
0:12:07 > 0:12:09in a blast furnace.
0:12:09 > 0:12:11What is a blast furnace?
0:12:11 > 0:12:15It's like a huge oven used to melt the ingredients for steel making.
0:12:15 > 0:12:19What's interesting is we can never really turn the furnace off,
0:12:19 > 0:12:21because, once it cools, it takes so long to heat up again.
0:12:21 > 0:12:25- So it's on all year round. - How does a blast furnace work?
0:12:25 > 0:12:29I tell you what, we'll go outside and I'll show you, OK?
0:12:29 > 0:12:32So this is one of the enormous blast furnaces
0:12:32 > 0:12:36that melts the iron ore, coal and limestone -
0:12:36 > 0:12:39the ingredients that make steel.
0:12:39 > 0:12:42What happens is we put all the raw ingredients
0:12:42 > 0:12:44into the top of the furnace, until the iron is melted down
0:12:44 > 0:12:47into a white-hot pool of liquid iron at the bottom.
0:12:47 > 0:12:51The furnace is so hot, we're not allowed anywhere near it.
0:12:51 > 0:12:55- How hot is the furnace?- Do you know how hot the water in a kettle is?
0:12:55 > 0:12:58Well, a blast furnace is 20 times hotter than that,
0:12:58 > 0:13:00so it's very, very hot.
0:13:00 > 0:13:02How would you get it all out of the furnace?
0:13:02 > 0:13:06Once the metal is collected, we have two drill a hole
0:13:06 > 0:13:07into the bottom of the furnace.
0:13:07 > 0:13:11The red-hot liquid drains into special containers
0:13:11 > 0:13:15on trains called torpedoes, which will take the liquid
0:13:15 > 0:13:18to the next part of the process - to turn it into steel.
0:13:22 > 0:13:25The liquid metal, at this stage, is full of impurities,
0:13:25 > 0:13:28so the next process is to clean it.
0:13:40 > 0:13:42How do you clean it?
0:13:42 > 0:13:45A special lance is lowered down to the surface of the liquid.
0:13:45 > 0:13:49A really fast gas is blown onto the top of the liquid.
0:13:49 > 0:13:51This makes all the impurities, and everything else
0:13:51 > 0:13:54in the steel that we don't want, float to the surface so we can
0:13:54 > 0:13:57scoop it away, then we're left with the steel that we need.
0:13:57 > 0:14:00Once the steel is cleaned,
0:14:00 > 0:14:04the next stage is to turn it from a liquid into a solid.
0:14:04 > 0:14:07When does it start looking like steel?
0:14:07 > 0:14:09First, we have to cool the red-hot liquid into a solid,
0:14:09 > 0:14:13then we can roll it thinner. Shall we go and see what we do next?
0:14:14 > 0:14:17The red-hot liquid steel is moulded into giant slabs
0:14:17 > 0:14:22and then the next process is to roll it, to make thin sheets of steel.
0:14:30 > 0:14:33The slabs from the steel plant are still too thick
0:14:33 > 0:14:34to be made into biscuit tins,
0:14:34 > 0:14:37so this is where we bring it to make it even thinner
0:14:37 > 0:14:39and roll the slabs into steel sheets.
0:14:41 > 0:14:45How do you turn those slabs into thinner sheets?
0:14:45 > 0:14:48First, you have to reheat them.
0:14:48 > 0:14:51The steel slabs need to be reheated in a very hot oven,
0:14:51 > 0:14:54so they're soft enough to go through the rollers,
0:14:54 > 0:14:56which make them thinner and longer.
0:15:03 > 0:15:06Then we can cut them, trim them and roll them into big coils,
0:15:06 > 0:15:09which look like giant toilet rolls,
0:15:09 > 0:15:12which can sometimes be up to a kilometre long.
0:15:12 > 0:15:14That does look like a giant toilet roll!
0:15:14 > 0:15:17It also looks very, very hot.
0:15:19 > 0:15:22- It doesn't look anything like biscuit tins.- You're right.
0:15:22 > 0:15:24First, we need to send them to another process
0:15:24 > 0:15:28to make them even thinner again.
0:15:28 > 0:15:32Then we can take it to the factory to make it into biscuit tins.
0:15:32 > 0:15:36So, at the end of this process, the red-hot steel is cooled
0:15:36 > 0:15:38and rolled even thinner.
0:15:38 > 0:15:42It is then ready to be made into biscuit tins.
0:15:42 > 0:15:46Chris is taking the children to see how this is done.
0:15:47 > 0:15:49So here we are at the factory
0:15:49 > 0:15:52where we take the steel and make it into biscuit tins.
0:15:52 > 0:15:55As you can see,
0:15:55 > 0:15:58the steel has been rolled really thin by the steel factory.
0:15:58 > 0:15:59We cut it into small sections,
0:15:59 > 0:16:01so we can put it through the machines.
0:16:01 > 0:16:05The thin sheets of steel are loaded onto the machine
0:16:05 > 0:16:07that cuts them into different sizes.
0:16:07 > 0:16:11This way, you can make different-sized biscuit tins.
0:16:25 > 0:16:28Once the sheets have been cut into the right sizes,
0:16:28 > 0:16:31the biscuit tin designs are printed on them.
0:16:44 > 0:16:46These have just come back from the printers.
0:16:46 > 0:16:50As you can see, they've got the same design on them.
0:16:50 > 0:16:52This will make about 15 biscuit tins.
0:16:52 > 0:16:54Do you think it looks more like a biscuit tin now?
0:16:54 > 0:16:56BOTH: Yes.
0:16:58 > 0:17:02Next, the printed sheets are cut even smaller...
0:17:04 > 0:17:09..and then pressed to make the biscuit-tin shapes.
0:17:17 > 0:17:19Here, the cylinders are about to go into this machine.
0:17:19 > 0:17:21This is where the bottom is put on to them.
0:17:32 > 0:17:36And after one last check, the biscuit tins are finished.
0:17:36 > 0:17:39They are now ready to be filled with biscuits.
0:17:45 > 0:17:50Now, our lids and our cylinders make a finished biscuit tin.
0:17:50 > 0:17:52- Thank you.- One for you.
0:17:54 > 0:17:56- And one for you.- Whoa!
0:17:58 > 0:18:01Hello, children, what did you find out?
0:18:01 > 0:18:05First, we went to see the ingredients - coal,
0:18:05 > 0:18:07iron ore and limestone.
0:18:07 > 0:18:10They were mixed together and melted in huge furnaces
0:18:10 > 0:18:12that look like big ovens.
0:18:12 > 0:18:17The liquid was poured into a transporter called a torpedo.
0:18:20 > 0:18:23This then cooled into big slabs.
0:18:23 > 0:18:26The slabs get flattened and stretched.
0:18:26 > 0:18:31They are then rolled and look like massive toilet rolls.
0:18:31 > 0:18:34The steel rolls are made even thinner
0:18:34 > 0:18:37and sent to the biscuit-tin factory.
0:18:37 > 0:18:41That's where the rolls get shaped into tins.
0:18:41 > 0:18:42It was brilliant.
0:18:42 > 0:18:44Well done, children.
0:18:44 > 0:18:47Now you know how steel is made and how a biscuit tin is made.
0:18:47 > 0:18:49Excellent work.
0:18:49 > 0:18:52See you next time. Bye for now.
0:18:52 > 0:18:54BOTH: Goodbye, Curious Cat.
0:18:54 > 0:18:56Goodbye, children.
0:19:22 > 0:19:27- Hello, children. - Hello, Curious Cat.
0:19:27 > 0:19:31Thank you for switching the lights on. It was a bit dark in here.
0:19:31 > 0:19:33It's a good thing we have lights,
0:19:33 > 0:19:35but do you know what makes them work?
0:19:35 > 0:19:37Is it electricity?
0:19:37 > 0:19:38That's right, children.
0:19:38 > 0:19:41Electricity is very important.
0:19:41 > 0:19:45We use it every day in all sorts of gadgets and gizmos.
0:19:45 > 0:19:48Electricity makes all sorts of things work,
0:19:48 > 0:19:51from little things, like hairdryers...
0:19:52 > 0:19:56..to big things, like all the lights in our houses and schools.
0:19:56 > 0:19:58That's because it's a type of energy.
0:19:58 > 0:20:02In the same way that you eat food to keep you going,
0:20:02 > 0:20:06machines and gadgets eat electricity to keep them going.
0:20:06 > 0:20:09But do you know how electricity is made
0:20:09 > 0:20:11and how it gets to the sockets in your home?
0:20:11 > 0:20:13BOTH: No.
0:20:13 > 0:20:18Well, to find out, you will need to visit the electricity power plant.
0:20:18 > 0:20:21- My friend Mark is waiting to show you round.- Hurray!
0:20:21 > 0:20:23Off you go!
0:20:30 > 0:20:34Electricity is made in a place called a power station.
0:20:34 > 0:20:36There are power stations all over the country
0:20:36 > 0:20:40and each needs to be fed fuel to make it run.
0:20:40 > 0:20:44Different power stations use different types of fuel.
0:20:44 > 0:20:48Some use coal, some oil, and some even use rubbish.
0:20:48 > 0:20:53All of these fuels are burned to get energy.
0:20:53 > 0:20:56But we can also use energy from the wind and flowing water.
0:20:56 > 0:21:00Even the sun can be used to make electricity.
0:21:01 > 0:21:05This power station is fuelled by gas.
0:21:05 > 0:21:07- Should we go and have a look? - BOTH: Yes!- Let's go.
0:21:11 > 0:21:14These are the biggest pipes I've ever seen!
0:21:14 > 0:21:18What you can see is the natural gas fuel
0:21:18 > 0:21:20that comes into the power station.
0:21:20 > 0:21:22The gas comes from deep underground
0:21:22 > 0:21:25and, because it is colourless, you cannot see it.
0:21:25 > 0:21:30That's why it has to travel into the power station
0:21:30 > 0:21:31in these great big pipes.
0:21:31 > 0:21:35It comes all the way through our pipework.
0:21:35 > 0:21:38It goes through into our buildings and gets burned.
0:21:38 > 0:21:40So the first stage of the process
0:21:40 > 0:21:44is to burn the natural gas to create heat.
0:21:45 > 0:21:50That heat then turns water into steam.
0:21:50 > 0:21:53Steam like from a kettle. Very hot.
0:21:53 > 0:21:57OK, from here, shall be going see where these pipeworks go
0:21:57 > 0:21:59and see where the steam is made?
0:21:59 > 0:22:01- Yes?- BOTH: Yes!- OK.
0:22:02 > 0:22:05We are now in the steam turbine hall where steam comes together
0:22:05 > 0:22:08and goes through the turbine.
0:22:08 > 0:22:10It passes through the blades
0:22:10 > 0:22:13and turns that turbine to help create energy.
0:22:13 > 0:22:17As an example, I've got these two little windmills for you.
0:22:17 > 0:22:23If you blow into them from the front, you can see they spin. Yes?
0:22:23 > 0:22:27If you think of your breath pushing that windmill around,
0:22:27 > 0:22:30it's just like steam turning round the turbine.
0:22:32 > 0:22:35The blades inside the steam turbine are really big.
0:22:35 > 0:22:39They can be up to a metre high or really small.
0:22:39 > 0:22:40Here's one to show you.
0:22:41 > 0:22:45So it's quite a bit different to what you've got in your hands.
0:22:45 > 0:22:46It does the same job.
0:22:46 > 0:22:50How can it turn around when it's so big and heavy?
0:22:50 > 0:22:55The steam turbine can turn, although it's metal and heavy,
0:22:55 > 0:22:58through the power from the steam coming through the blades
0:22:58 > 0:23:00and turning them round.
0:23:00 > 0:23:02I know that's hard to imagine -
0:23:02 > 0:23:04steam so powerful to push those heavy blades,
0:23:04 > 0:23:08so Mark has a demonstration, to show the girls how it all works.
0:23:08 > 0:23:11OK, girls, I promised showing you electricity,
0:23:11 > 0:23:12here's a demo of it.
0:23:12 > 0:23:16At the power station, we have gas coming in
0:23:16 > 0:23:18that's burned to create our steam.
0:23:18 > 0:23:23Here we have a gas cylinder, which will be set light to.
0:23:23 > 0:23:26It will heat up the water inside the kettle.
0:23:26 > 0:23:28The steam from there will come through there
0:23:28 > 0:23:34and out the spout to turn these spoons,
0:23:34 > 0:23:37which is just like our steam turbine out on the plant.
0:23:37 > 0:23:41Once this starts to turn, we can then generate electricity
0:23:41 > 0:23:45through the cable to our houses and the streetlight.
0:24:11 > 0:24:12Wow!
0:24:12 > 0:24:13Wow!
0:24:19 > 0:24:22That's amazing!
0:24:22 > 0:24:25Once the kettle has boiled, the steam pushes out of the spout
0:24:25 > 0:24:29and turns the turbine made of spoons.
0:24:29 > 0:24:33So now we know that an electricity power plant
0:24:33 > 0:24:36can use different types of fuel to make steam to spin a turbine.
0:24:38 > 0:24:41But how does this actually make electricity?
0:24:41 > 0:24:44The answer involves a magnet and a coil of wire.
0:24:44 > 0:24:50You can see there's plenty of wire that's turned round this plastic.
0:24:50 > 0:24:53You have one of these on your steam turbine.
0:24:53 > 0:24:59If I put a magnet inside, and shake it, what can you see?
0:24:59 > 0:25:01BOTH: The light.
0:25:01 > 0:25:03Yes, that's right.
0:25:03 > 0:25:07The turbine moves a magnet that spins inside some wires.
0:25:07 > 0:25:11This generates electricity in the wires.
0:25:11 > 0:25:16The electricity travels down the wire and lights up the lamp.
0:25:16 > 0:25:19How much electricity do you make here?
0:25:19 > 0:25:24The power station can provide enough electricity to power London.
0:25:24 > 0:25:26- Shall I show you the control room? - BOTH: Yes!
0:25:26 > 0:25:29Wow, that is a lot of electricity!
0:25:39 > 0:25:42This is where we control the electricity
0:25:42 > 0:25:46going out to major cities, homes, towns, in the country.
0:25:46 > 0:25:48Sometimes, we need a little,
0:25:48 > 0:25:50sometimes we need a lot of power to go out there.
0:25:50 > 0:25:53When do we need lots of electricity?
0:25:53 > 0:25:56Early in the morning, when everybody is waking up,
0:25:56 > 0:25:59so a lot of electricity is going to be used then, and, of course,
0:25:59 > 0:26:01when we come home from school, from work,
0:26:01 > 0:26:05that is another time when we need to provide a lot of power.
0:26:05 > 0:26:09How does the electricity get to our homes?
0:26:09 > 0:26:11If we go outside, I can show you.
0:26:30 > 0:26:31OK, girls,
0:26:31 > 0:26:34now you can see the end of the process.
0:26:34 > 0:26:38Here, you can see these large cables going up to this pylon.
0:26:38 > 0:26:42These long cables go all the way round the country
0:26:42 > 0:26:47and take the electricity to towns, cities and your home.
0:26:47 > 0:26:49What are the cables made of?
0:26:49 > 0:26:53They are made of a metal material to conduct the electricity.
0:26:53 > 0:26:58A conductor is a material that electricity can flow through easily.
0:26:58 > 0:27:01When you put a plug into a socket,
0:27:01 > 0:27:04the electricity travels through the metal pins
0:27:04 > 0:27:06and not the plastic casing.
0:27:06 > 0:27:11This is because metal is a good conductor and plastic is not.
0:27:11 > 0:27:14That's why electrical wires are made of metal.
0:27:16 > 0:27:18The pylons support the metal cables
0:27:18 > 0:27:21and take the electricity across the country.
0:27:21 > 0:27:26All the pylons and wires together are called the National Grid.
0:27:26 > 0:27:29These pylons and wires are very dangerous
0:27:29 > 0:27:31and you should not go anywhere near them.
0:27:31 > 0:27:36This is how electricity gets to your homes.
0:27:36 > 0:27:39How it powers your kettles, your toasters, your ovens,
0:27:39 > 0:27:42the things you use on a day-to-day basis.
0:27:44 > 0:27:46Hello, children, how was your journey?
0:27:46 > 0:27:49- It was great.- Yes.
0:27:49 > 0:27:51What did you find out about electricity?
0:27:51 > 0:27:56That electricity can be made out of different fuels, like coal and gas.
0:27:56 > 0:28:00And it's made in a power plant, where it gets really hot,
0:28:00 > 0:28:02and spins a turbine, which has a magnet
0:28:02 > 0:28:06that spins in the middle of some wires.
0:28:06 > 0:28:10This makes electricity in the wire.
0:28:10 > 0:28:12The electricity goes through the wire
0:28:12 > 0:28:16and is sent all over the country through cables
0:28:16 > 0:28:19and ends up in our homes.
0:28:19 > 0:28:22Wow! That's brilliant work.
0:28:22 > 0:28:26You know all about generating electricity. Well done, you two.
0:28:26 > 0:28:28Now, I think it's time to say goodbye.
0:28:28 > 0:28:34Don't forget to turn the lights off on your way out! Goodbye.
0:28:34 > 0:28:37BOTH: Goodbye, Curious Cat.
0:28:37 > 0:28:39Goodbye, children.
0:28:55 > 0:28:58Subtitles by Red Bee Media Ltd