Lesson video

Hello, my name is Mr. Marsh, and I'm here today to teach you all about strategies to increase energy supply.

So grab everything that you need for today's lesson and let's get going.

So by the end of today's lesson, you will be able to assess strategies used to increase energy supply and use an example to support your answer.

There are four key terms for today's lesson, and those are carbon emissions, biomass, hydro, and finally, viable.

Carbon emissions refers to the release of carbon into the atmosphere, contributing to the greenhouse effect and global warming.

Biomass refers to organic matter from plants and animals used as a fuel source to produce energy.

A biofuel is a biomass converted into a liquid or gas fuel which can be used in place of oil and natural gas.

Hydro refers to the process of using moving water to generate electricity, also known as hydroelectric power, or HEP.

And finally, viable refers to being able to generate enough money to cover its costs and remain profitable.

There are two learning cycles for today's lesson.

I'm gonna start with learning cycle one, which is all about strategies for increasing energy supply.

So we're gonna start today's lesson with a really interesting graph.

Now, this graph on the right-hand side is showing global energy consumption by source, and what does this graph actually tell us? Well, first of all, what is it telling us in terms of energy demand? We can see the graph beginning in 1800 all the way up to 2023.

What is it telling us about energy demand? Also, what is it telling us about what sources of energy are being used to actually meet that demand? Now, you may like to pause the video here whilst you really study that graph to try to answer those two questions, or perhaps even better, have a discussion with someone near you.

So let's now start with that first question.

What did you come up with? Well, Lucas also has an answer.

Lucas says that demand has increased rapidly over the last 70 years or so, from 30,000 terawatt hours to 180,000 terawatt hours.

And indeed, if we look at the graph, you can see that sudden increase really in the last 70 years.

What about in terms of the sources of energy, the types of energy sources that are being used to meet this demand? Well, again, Lucas says a really good answer.

We can see that renewables have grown as a source of energy, but I'd estimate that around 80% of energy is still coming from fossil fuels such as oil and coal.

So really, really well done if you're able to identify the same answers that Lucas has just come up with.

Now, realistically, there are two main strategies for trying to increase energy supply, the first of which is to increase the supply of non-renewables, so fossil fuels, for example, and the second is to increase the supply of renewable energy types, such as solar and wind.

Non-renewables, as I just said, include fossil fuels, and now my question to you is, why are most countries looking to reduce their dependence on fossil fuels? Now, once again, you may like to pause the video here whilst you consider your own answer to that question, or better still, once again, have a discussion with someone near you.

Now, increasing fossil fuel energy supply has many, many different disadvantages, and it really comes back to this question right here, which is, why are most countries looking to reduce their dependence on fossil fuels? Well, really, it comes back to increasing carbon emissions is the main problem with increasing the energy supply by supplying more fossil fuels.

Adding more carbon dioxide to the atmosphere will intensify the rate of global warming and therefore the impacts of climate change, which is why international agreements have instead been made that set targets for each country to reduce their emissions in the hope of avoiding the worst where climate change impacts are concerned.

Energy security is about achieving a reliable supply of energy that meets people's needs.

For many countries, increasing the supply of fossil fuel energy reduces energy security because these supplies have to be imported.

Furthermore, reserves are running out.

As the easy to access oil, gas and coal are used up, countries have to spend more money getting at remaining less accessible supplies until those too are used up.

Non-renewable energy is finite.

Next we have air pollution.

Now, air pollution is a major problem in many cities around the world, caused at least in part by burning fossil fuels for transportation and energy generation.

Meeting rising demand for more petrol and diesel cars, for example, adds to the air pollution problem and its often severe health impacts.

Developing new sources of fossil fuels is often in areas that have previously not been developed because of their remoteness, challenging conditions, or environmental sensitivity, such as the Arctic, for example.

As we will see in the second part of this lesson, drilling for oil and gas in such conditions poses high risks for habitats and species.

In the same way, clearing forests to mine coal or extract oil from tar sands deposits can have very severe environmental impacts.

And finally, there's also a high cost to developing new sources of fossil fuel energy in remote locations, such as the cost of building pipelines to transport the oil.

Now let's look at developing renewable sources of energy.

Biomass, hydro, solar and wind are all renewable sources of energy.

Renewable means the energy comes from sources that don't run out or are quickly renewed or replaced, and now as we can see on the graphic on the right-hand side, renewables now generate over 50% of the UK's electricity, and when we compare that with 1990, we can see the vast increase in that electricity generation.

So let's now look at the advantages of using biomass.

Well, first of all, it's carbon neutral.

The carbon released when biomass is burnt is offset by the carbon that's absorbed as the plant is actually growing.

Biofuels can also be mixed with petrol and diesel, which can keep transportation costs lower at times of high oil prices.

Growing biofuels would reduce a country's need to import petrol and diesel, increasing energy security.

And finally, renewables can power electric vehicles, but for petrol and diesel vehicles, then biofuels provide a carbon-neutral option.

And what about the disadvantages then? Well, rainforest is often cleared, unfortunately, to grow crops for biofuels.

Deforestation causes habitat destruction and increases atmospheric CO2.

Also, the amount of energy available for biofuels is lower than that we can get from fossil fuels.

So very, very large areas of land would need to be cleared to replace fossil fuel use.

Growing biofuels can also reduce the land available for growing food, leading once again to an increase in food prices.

Also, biofuels often require a lot of water, which can stress ecosystems and can also lead to land degradation as well as damaging habitats.

Time now for a learning check.

It says true or false, burning biomass for energy is a renewable source of energy because plants regrow quickly.

So what you need to do right now then is pause the video here whilst you consider, and then select your answer.

And the correct answer was true.

Now once again, I'd like you to pause the video here whilst you consider as to why that statement is true.

And the reason it's true is that renewable energy comes from sources that don't run out or are quickly renewed.

Because plants are quickly replaced, biomass is a renewable energy source.

Also, plants absorb CO2 as they grow, which is released when they burn.

So they're also carbon neutral as well.

Really, really well done if you were able to get those two answers correct.

So let's now look at the advantages of using hydro.

First of all, there are zero carbon emissions when generating electricity.

Hydro is a clean, renewable source of electricity.

Furthermore, hydro plants are very expensive to build, but they do last a long time once built and actually have very low maintenance costs.

It supports energy security by reducing reliance on imported fossil fuels, although not all countries actually have the large rivers that are required for really effective hydro projects.

And finally, hydro is reliable and predictable and can also be used to store renewable energy.

This makes it great for balancing energy supply from intermittent renewables, such as solar and wind, which only generate electricity when the sun is shining and when the wind is blowing.

And what about the disadvantages then of using hydro? Well, first of all, dams and reservoirs are very expensive to build, around $5 billion for a one-gigawatt dam and hydro plant.

Flooding land for reservoirs can mean loss of farmland and displacement of communities that would've lived there, and not all countries have the large river systems required for large-scale hydro.

So the potential for hydro may actually be limited.

Dams can disrupt river ecosystems and affect fish migrations while flooding river valleys for reservoirs can cause deforestation as well as habitat loss.

Moving on to solar and again the advantages.

Well, first of all, it generates electricity once again without any carbon emissions.

The costs of solar power have fallen dramatically, and households can actually add solar panels to roofs to reduce energy costs.

It increases energy independence, especially when lots of households are able to generate some of their own electricity, and it's also good for balancing a country's energy mix, especially for higher latitudes in summer when days are really long and potential for solar is at its highest, but what about the disadvantages? Well, although costs have reduced significantly with regards to solar power generation, the cost of installation can still be too high for homes, school buildings, offices, et cetera.

There is often opposition to large-scale solar farms because of the big impact they have on farming as well as natural habitats.

Solar only works in daylight and is best in summer in higher latitudes, while power is actually still needed 24/7 and all year round.

So it's only really truly effective perhaps during those summer months.

Manufacture of solar panels include toxic chemicals, and systems to recycle panels safely after they stop working are not yet fully developed.

So it's not 100% environmentally friendly.

So let's now have a look at the advantages of using wind power.

So first of all, there are zero carbon emissions when generating electricity.

Wind is a clean, renewable energy source.

Wind farms can be built offshore, so in the sea, so they don't actually take up land area, and the UK has some of the world's best offshore wind resources in the North Sea.

Wind energy is now one of the cheapest sources of electricity in countries like the UK, and wind supports energy security by reducing reliance on imported fossil fuels.

Wind can also be combined with solar to balance supply, for example, at night when solar power isn't actually working.

And what about the disadvantages then of wind turbines? Well, once again, they are expensive to build, especially for offshore wind farms, which need underwater foundations as well as cables to the shore.

Furthermore, turbines have a big impact on landscapes and can be noisy, which leads to local opposition to wind farms, especially if they're on shore.

Furthermore, no power if there's no wind, which means other sources of power or power backups will always be needed.

And finally, turbines can actually kill birds and bats if they fly into the blades.

Turbine construction also disturbs habitats onshore and offshore, for example, seabeds.

Time for our next learning check, and it says, which two of the following are costs associated with both solar and wind energy? So you can see you've got four different options on the screen there.

What you need to do is pause the video here whilst you read through those four options and select what you think are the two correct answers.

And the two correct answers are, a, landscape impacts which are often opposed locally, and c, intermittent supply rather than always being available.

Really well done if you're able to select a and c as the correct answers.

Now, let's now look at nuclear power because nuclear power requires uranium, which is a non-renewable resource.

It is finite.

It will run out.

As a result, nuclear power is classed as a non-renewable energy source.

Aisha says though, "I thought nuclear fuel could be recycled and used again." Well, it is possible to recover uranium from spent fuel rods and use it again, but it is expensive, and not all countries are able to do this.

So let's now look at the advantages of using nuclear power.

First of all, it's a low carbon source of electricity.

No CO2 is actually released during power generation.

Nuclear power stations can be built in a wide range of locations.

All they need is, really, lots of water for cooling.

So by coast, by rivers are usually greater locations for nuclear power stations, and a low risk of tectonic hazards is a also really, really important consideration.

Building nuclear power plants is very, very expensive, but once they're running, the cost of power is low.

Nuclear power could replace fossil fuels because nuclear power reactions produce an enormous amount of energy.

And finally, nuclear power is 24/7 and isn't dependent on weather.

So it's ideal for balancing less reliable supply from perhaps wind and solar energy.

And what about the disadvantages then of using nuclear power? Well, first of all, it's very expensive to build, and construction can take many, many years.

For example, Hinkley Point C in the UK has an estimated cost of 46 billion pounds.

Spent nuclear fuel is also extremely radioactive.

If it is not recycled, then it has to be stored securely for at least 10,000 years.

Climate change means sea level rises and increased coastal erosion, both of which are threats to nuclear power stations which are located along the coastline.

And finally, people would of course prefer not to live next to a nuclear power station because of fears about accidents, even though they're extremely rare.

Time once again for a learning check, and it says, which of the following sources can provide constant and predictable supplies of energy 24/7? So you can see you've got four different options on the screen there.

What you need to do is pause the video here whilst you consider and then select all the answers that you think are correct.

And the correct answers are biomass, fossil fuels, and nuclear, and as Andeep says, "Solar energy is not constant because it only generates energy when there is sunlight." And as Laura says, "And solar isn't predictable in countries like the UK." So really well done if you're able to get a, b, and c as the correct answers.

We're on now to our two practise tasks for our first learning cycle.

The first one says to read the information about tidal and geothermal energy.

What advantage do these energy sources have compared to solar and wind? The second and final question says that the UK plans to achieve net zero by 2050.

This means that the UK greenhouse gas emissions would equal greenhouse gases removed from the atmosphere by the UK.

So looking at the UK's current energy mix, which you can see in that pie chart on the screen in front of you, what strategy would you recommend to reduce greenhouse gas emissions while still supplying enough energy to meet the UK's needs? So please then pause the video here whilst you attempt these two practise tasks.

Best of luck.

So let's now have some feedback for the first question.

Now, your answer may have included the following.

The main advantage of both tidal and geothermal energy over wind and solar is that these sources provide reliable and predictable energy while wind and solar can be intermittent and unpredictable.

Solar only works when there's enough sunlight, so no supply at night, for example, while wind only provides enough energy or provides energy when enough wind is blowing to turn the turbines.

And now for the second question.

Now, you may have said something like this.

I've said that my top recommendation would be to increase supplies from wind because the UK has some of the world's best offshore wind resources in the world.

Wind is already a significant part of the UK's energy mix, up at 11%.

The electricity it generates is zero emissions, and wind energy is already one of the cheapest sources of electricity in the UK.

Getting as much energy supply from renewable wind energy is therefore really important for achieving net zero and should increase energy supplies in an affordable way as well.

The answer continues.

However, I would also recommend that the government invests in nuclear power to meet the UK's electricity needs.

It costs a lot to build nuclear power stations, but the electricity it provides is then available 24/7, unlike wind, which is dependent on weather conditions.

Although it is a non-renewable source of energy and does rely on supplies of uranium from other countries, which can affect energy security, nuclear produces zero-emission energy, which would help the UK meet net zero targets, and nuclear reactions produce huge amounts of energy, enough to supply the UK's needs.

So really, really well done if you're able to include anything like that in your own answer.

We're on now to our second and final learning cycle, and this is all about the advantages and disadvantages in Alaska.

So Point Thomson, which is near Deadhorse, Alaska, is an example of where the USA is developing new sources of oil and gas, and you can see that perfectly mapped there on the screen in front of you.

Extracting fossil fuels here has both advantages and disadvantages, which we're now going to explore.

Now, Point Thomson is located on the coastline of the Beaufort Sea, as you can see on the map in front of you, in a region of Alaska called North Slope.

North Slope is isolated from the rest of Alaska by a mountain range called the Brooks Range, and there is just one highway connecting North Slope to Fairbanks, which is 500 miles to the south.

Now, Fairbanks is Alaska's second largest city after the state capital, Anchorage.

Around 33,000 people live in Fairbanks.

Now, what are the advantages of the Port Thomson project? Well, US geologists estimate that North Slope holds 22 billion barrels of oil and 230 trillion cubic feet of gas, and this adds 50% more oil and 30% more gas to the US's existing reserves.

Port Thomson has estimated to have around 200 million barrels of oil and around 8 trillion cubic feet of gas.

Now, as Yun says, "Having lots more oil and gas to sell is a big economic advantage," and as Sam says, "Yes, and extracting more oil and gas from Alaska would mean the USA would have more energy security too." Currently, Port Thomson produces around 5,000 barrels of oil a day, and the oil goes into a pipeline to Prudhoe Bay, where it joins the Trans-Alaska Pipeline System, otherwise known as TAPS or TAPS.

The trans-Alaska pipeline is 800 miles long and delivers North Slope oil to Valdez, and Valdez is a warm water port.

Valdez is a port on the Gulf of Alaska, which stays ice free all year round, unlike the Beaufort Sea.

So it's much more accessible and safe rather than perhaps going around to Beaufort Sea to collect that oil.

Time now for a learning check, and it says true or false, the Trans-Alaska Pipeline System helps Point Thomson to be economically viable.

So what you need to do then is pause the video here whilst you consider whether that statement is true or false.

And the correct answer is true.

Now, once again, I'd like you to pause the video here whilst you consider as to why that statement then is true.

And the reason it's true is that the Trans-Alaska Pipeline System transports oil from Prudhoe Bay to the ice-free Port of Valdez in South Alaska.

The Beaufort Sea is frozen for most of the year.

So without TAPS or TAPS, Point Thomson would not have a cost-effective way of transporting its oil where it could then sell it.

Now, really, really well done if you're able to get those two answers correct, but what other advantages has the Port Thomson project brought? Well, constructing the Point Thomson project has created jobs.

For example, 99 companies from Alaska were involved in building the facility.

1,100 Alaskans worked at Point Thomson during construction, and around 200 people are still employed there now.

Alaska will also get 25% of all sales of Point Thomson oil and gas, but as Aisha says, "Doesn't it cost a lot to extract oil and gas in Alaska?" Well, now we're gonna spend the part of the lesson where we look at the disadvantages of the Point Thomson project, and indeed, the project does face many challenges, and they include its remote and isolated location.

Connecting Point Thomson to TAPS required a 22-mile-long insulated pipeline.

Equipment has to be flow in and out of the base, which of course is very expensive, but what also about the polar climate? Workers have special training to stay safe in temperatures of minus 40 degrees Celsius and below.

Machinery also needs special lubricants and heating systems in order to work during those cold conditions.

Pipelines also have to be insulated to prevent permafrost from melting, and fences are also needed to keep away polar bears.

Furthermore, high pressure oil and gas.

Well, the oil and gas at Point Thomson is under huge pressure and specialised machinery is needed to actually deal with this high pressure.

The cost of upgrading drilling equipment was estimated to be around 35 million US dollars, but also there's no pipeline yet for gas.

The gas and oil come out together, but because there's no way yet of transporting the gas to market, the gas has to be pumped back underground, which adds to the cost.

The North Slope region is also ecologically extremely important because it includes the USA's largest natural wildlife refuge, which is called the Arctic Natural Wildlife Refuge, and some species include here the polar bears, grizzly bears, black bears, caribou, which migrate each and every year to North Slope to actually breed.

There are also wolves, Arctic foxes, Canada lynx, and also wolverines.

There are also hundreds of species of migratory birds.

Walrus, seals and bowhead whales can also be found here.

So North Slope is also a traditional homeland of the Gwich'in people.

The caribou is central to the traditions of these indigenous Gwich'in people.

So let's now touch a little bit more on that caribou migration because extracting fossil fuels in North Slope does indeed cause many environmental challenges.

In order to allow for caribou migration, the pipeline to Prudhoe Bay has to be raised seven feet above the ground, and this required 2,200 supports to be constructed to support the pipeline.

Furthermore, there are fragile coastal ecosystems. Now, oil wells were drilled using long-reach directional drills, which, yes, are more expensive, but having the wells offshore does reduce the impacts on the Alaskan coastline.

But what about the social implications? Because actually not everyone locally or indeed in the USA supports fossil fuel extraction in North Slope, let's look at the indigenous rights, the rights of the indigenous peoples because the oil and gas company investing in Point Thomson involves local indigenous communities in their planning and has donated money into a fund for community facilities.

Furthermore, let's look at the legal challenges because gas was first discovered at Point Thomson in 1975.

The company submitted 20 development plans before the first two wells were drilled in 2009, following numerous court challenges.

So you can see that it took 34 years between oil being discovered and the first two wells being drilled.

So time now for a learning check, and it says to match the problem to the Point Thomson solution.

So you can see on the left then you've got those different problems, such as polar bears, caribou migration, no gas transportation, et cetera, and on the right-hand side, then you've got the proposed solution taken from the example of Point Thomson.

So please then pause the video here whilst you attempt this learning check.

And the correct answers are, so polar bears, well, they built fences.

Caribou migration, they raised the pipeline seven feet into the air to prevent permafrost from melting.

No gas transportation, well, they pump gas back into the ground.

High pressure oil, they now use specialised and expensive machinery.

And finally, no roads, well, they transport equipment in and out by air.

Really, really well done if you're able to match those five different problems to the Point Thomson solution.

We're on now to our two final practise tasks for our final learning cycle, and the first one says to describe three disadvantages of extracting fossil fuels at Point Thomson, Alaska.

The second question says to explain the advantages of extracting fossil fuels at Point Thomson, Alaska.

So please then pause the video here whilst you attempt these two practise tasks.

Best of luck.

In terms of feedback then for the first question, now, your answer may have included the following.

"Because Point Thomson is a long way from where the oil or gas can be sold, a 22-kilometer-long pipeline had to be constructed to transport it to Prudhoe Bay, where it could then connect to TAPS.

Pipelines are very expensive to construct and maintain.

Pipelines can be a problem in Alaska because they get in the way of migrating animals like caribou.

One solution is to raise the pipeline up into the air so the animals can actually pass underneath it.

This means animals can migrate, but it adds a lot to pipeline costs." The answer continues.

"In order to avoid causing damage to ecologically sensitive areas, special equipment is required.

For example, to avoid melting permafrost, pipelines need to be insulated, which does unfortunately add to their cost.

To avoid disrupting coastlines, long-reach directional drills were used.

The oil and gas at Point Thomson are under high pressure and so specialised machinery is needed to deal with this high pressure.

The cost of upgrading drilling equipment for Point Thomson was 35 million US dollars." And what about the second question? Well, once again, you may have answered the following.

"I've said that Alaska's North Slope adds 50% to the US's oil reserves and 1/3 more to its gas reserves.

This increases the USA's energy supply, providing it with a lot more energy to sell or to use for itself, which is a big economic advantage.

The USA has already invested in TAPS, an 800-mile pipeline that transports oil from North Slope to southern Alaska, from where it can be transported by ship to markets in the rest of the USA and the rest of the world.

Point Thomson is able to send its oil along this pipeline too.

Without TAPS, Point Thomson might not be viable." The answer continues.

"Other advantages to the USA are that people in this isolated area of Alaska can get jobs and that states like Alaska can earn a percentage of the oil or gas sales.

That can be important for areas that don't have many other industries or services for people to work in.

Looking to the future, if countries around the world keep using oil and gas, then there might be a time when other non-renewable energy sources have run out.

Then the USA will be glad that it spent the money on developing its oil and gas reserves in Alaska, even though it cost a lot of money to do it." So really well done if you're able to include anything like that in your own answer.

We're on now to our learning summary and what you need to know from today's lesson.

Well, you need to know that demand for energy is rising globally, as the graph on the right-hand side does a great job in illustrating.

Supplies of fossil fuels can be increased, but this does have severe environmental impacts and can also be costly and difficult.

And finally, renewables are vital for reducing carbon emissions but have disadvantages that limit their ability to fully replace fossil fuels immediately.

So really, really well done during today's lesson.

It was a pleasure teaching you, and I will see you again on the next lesson.

Goodbye.