Transcription
Welcome to this 2 to to you topic video that looks at increasing energy supply. This is part of Paper 2, Unit C, the challenge of resource management.
There are many different solutions to increasing energy supply and ensuring energy security across the globe. But we need to ensure that these strategies don't harm the environment, are affordable, and can be exploited with the technology available to us.
Fossil fuels are the dominant energy source around the globe, accounting for about 80%. However, climate change has forced governments to rethink our use of coal, oil, and gas and turn to alternative energy sources to reduce carbon emissions. This video is looking at the different energy options available to us.
The first alternative energy source that we're going to discuss is nuclear energy. Nuclear energy accounts for just 5% of global energy production. It works by nuclear fission using uranium. This process takes place in a nuclear reactor and generates heat and steam, which drives turbines to generate energy. Because it uses a mineral, uranium, nuclear power is classed as a non-renewable energy, as a mineral is finite, so it will eventually run out. However, it only needs very small quantities of uranium and emits minimal carbon dioxide during production, so it is better for the environment than fossil fuels. It is also able to produce energy at a large scale, which many other alternative energy sources can't.
But nuclear power is controversial for many reasons. Economically, the power stations cost an enormous amount of money to construct, so therefore are not suitable for low-income countries or many newly emerging economies. Transportation and storage of nuclear waste is also difficult and expensive, and the decommissioning process at the end of the life of the power station costs a lot of money. Also, environmentally, nuclear waste has to be stored for a very long time. It can take thousands of years for radioactive decay to occur, so the risk of contamination is high. In addition, radiation leaks from nuclear accidents can have a long-term effect on people and the environment. For example, Chernobyl in Ukraine in 1986. This led to the evacuation of 350,000 people and destroyed hundreds of thousands of pine trees close to the reactor. This led to reduced seed production in the area and a huge decline in species of invertebrates and small animals.
In the late 1990s, nuclear power accounted for a quarter of all energy production in the UK, but this has declined to around 15% now. Other countries have also decided to change their stance on nuclear energy. The Japanese government is considering closing down all of its nuclear plants, and Germany has stated that their future energy security will not be met through nuclear energy.
The next energy source that we're going to look at is wind power. Wind power works by turbines on land or at sea being turned by the wind to generate electricity. Once they are constructed, the cost to run wind turbines is quite low. They can be built offshore, so take up less valuable land and are less likely to be opposed. Improved technology also means that they require less maintenance, can generate more power, and are less noisy. There is a lot of potential for wind farms in upland areas around the world, as well as in the global deserts where land is exposed and there is nothing to slow the wind down. The Jaisalmer wind farm in the Thar Desert is India's biggest wind farm, and you can see a picture of that on the screen.
However, some people claim they ruin the landscape, particularly as they are often in upland areas with spectacular scenery, and they pose a danger to birds who often fly into the blades. They are also expensive to construct, and wind is unpredictable, so at certain times of the year they generate far less energy, and other times the energy generated cannot be stored.
Let's move on to solar power. Solar energy is generated by photovoltaic cells mounted together to make up huge solar panels. This technology converts sunlight into electricity. Solar panels are cheaper to install than some other renewable sources, easy and cheap to maintain, and have huge potential in low-income countries and newly emerging economies with sunny climates. For example, solar farms are currently being developed in the Thar Desert in India. The Ivanpah Solar Electric Power Facility, which is pictured on the screen, is in the Mojave Desert in California and is one of the world's largest solar farms. It generates power by using 173,000 heliostat mirrors, each measuring 7m², to focus sunlight onto three huge solar power towers, which are 130m high. The heat from the sun generates steam to drive turbines that generate electricity for 140,000 homes. The project cost $2.2 billion and covers 3,600 hectares of land.
However, environmental campaigners have expressed their concerns over the impact of this project on the fragile desert ecosystem. Vegetation has to be removed during construction, leading to the destruction of rare plants, and birds are confused by the mirrors, mistaking them for water, and are also killed by flying into the concentrated rays. Groundwater is also used to wash the mirrors, and finally, the habitats of the golden eagle and the bighorn sheep have been destroyed.
Of course, solar energy production is seasonal. For example, in a temperate climate, there are times of the year where solar panels wouldn't generate as much energy, and in some countries, it wouldn't generate much at any point in the year. Solar farms also take up lots of land, which people think could be used to produce food.
Many LICs and NEEs are turning to biomass for their energy production. Biomass is energy produced from organic matter, either through burning dung or plant matter, or the production of biofuels by processing specifically growing plants such as sugar cane. It can be produced domestically, so sources of biomass energy are widespread and easily available. It also reduces and makes use of waste, meaning less waste ends up in landfill.
However, it does cause deforestation, as rainforests are cut down to make way for biofuel plantations. These take up huge amounts of space, such as the Sorghum plantations, which are pictured on the screen. Additionally, when organic matter is burned, it emits harmful pollutants into the atmosphere, including carbon dioxide, which leads to the greenhouse effect and climate change.
Some countries are able to harness geothermal energy. This comes from water heated underground by hot rocks, creating steam that drives turbines to generate electricity. It doesn't emit any harmful gases and is very efficient, so can generate a lot of energy. For example, it provides over a third of Iceland's energy, and the Svartsengi plant, which is pictured on the screen, is one of six enormous geothermal power plants in the country. It is a constant source of energy, meaning that it is not dependent on wind or sun, and it's available all year long, making it much more reliable than other forms of renewable energy.
However, it is limited to tectonically active countries. For example, Iceland is on a constructive plate margin; in fact, it's on the Mid-Atlantic Ridge, and there are some concerns that these locations could cool down over time, making them unsuitable for geothermal energy. Extracting geothermal energy is also a really expensive process, so it's only an option for the HICs in tectonically active areas rather than many LICs who could potentially exploit it because of their proximity to plate margins.
The last type of energy that we're going to look at is hydroelectric power. Hydroelectric power, also known as HEP, is generated using dams where water turns turbines. These dams can be small-scale, or they can be huge engineering feats, such as the Hoover Dam on the Colorado River in the USA, which is pictured on the screen. Hydroelectric power makes up about 80% of all renewable energy generation across the globe, and it is very popular in HICs with big rivers. Water flow can be controlled in order to generate more electricity when the demand peaks.
However, it is very controversial, as the large dams are expensive and reduce the amount of water feeding rivers downstream, causing issues for local communities, such as not having enough water for farming and disrupting fish migration. They also cause mass flooding upstream, displacing local communities when the reservoirs are constructed. Did finally, the change in depth of water also has an impact on wildlife, which can't adapt to the change in water temperature.
That concludes this 2 to to you topic video focusing on increasing energy supplies. Thank you for watching.