Energy, Water, Environment

Non-Renewable Energy Sources

Type on non-renewable energy / Advantages / Disadvantages
Coal /
  • Energy production using coal can be increased or decreased according to demand
  • The technology to burn coal to generate electricity already exists
/
  • Coal is finite so will eventually run out.
  • Many existing reserves are becoming harder to extract or are in environmentally sensitive areas
  • Coal releases large amounts of greenhouses gases when burnt
  • Mining deep underground coal is very dangerous
  • Coal is very baulky and expensive to transport around the world

Oil /
  • Energy production using oil can be increased or decreased according to demand
  • The technology to burn oil to generate electricity already exists
  • Technology is improving to extract deeper reserves as well oil in tar sands (Canada).
/
  • Oil is finite so will eventually run out
  • A lot of oil is located in politically unstable countries or environmentally sensitive areas e.g. Libya and Iraq.
  • Oil can cause widespread pollution when spilt
  • Oil releases large amounts of greenhouse gases when burnt
  • Oil is vulnerable to large scale changes in its price
  • The production of oil refineries is expensive

Gas /
  • Energy production using gas can be increased or decreased according to demand
  • The technology to burn gas to generate electricity already exists
  • Burning gas releases less greenhouses gases then coal and oil
  • It is now possible to compress gas and transport it more easily.
/
  • Gas is finite so will eventually run out
  • A lot of gas is located in politically unstable countries or environmentally sensitive areas.
  • Gas is vulnerable to leaks and explosions

Nuclear /
  • Cheap
  • Produces large quantities of energy on demand
  • Does not produce greenhouse gases or other air pollutants
  • Enough raw material (Uranium) for 100s of years
/
  • Danger of Accidents
  • Waste is dangerous for 1000s of years
  • No way to dispose of waste safely
  • Water pollution from cooling material

Renewable Energy Resources

Type of Renewable Energy / Advantages / Disadvantages
Solar: Using the power of the sun to heat water or generate electricity.
/
  • It is a clean form of energy
  • It is a infinite resource
  • Panels can be used locally e.g. on top of someones house
  • It can be used to heat water and generate electricity.
/
  • It is expensive to make solar panels
  • The sun does not shine all the time
  • Not every country gets adequate levels of sun
  • They can't be used at night
  • It is hard store surplus energy
  • Supply does not always equal demand

Wind: Using the power of the wind to drive a turbine to generate electricity. /
  • It is a clean form of energy
  • It is an infinite resource
  • It can be used on a local scale e.g. in your back garden
  • Technology is proven
  • They can be placed at sea on in mountains away from settlements
/
  • Visual pollution (NIMBY - see below)
  • Noise pollution
  • Wind is unreliable
  • They are expensive to install, especially offshore
  • It is hard to store surplus energy
  • They have to be turned off in very strong winds

Tidal: Using the incoming and outgoing motion of the tide to generate electricity. /
  • It is a clean form of energy
  • It is an infinite resource, tides happen twice a day.
  • Ideal for island countries.
/
  • It can block important shipping routes
  • May interfere with some animals e.g. sea otters and seals
  • Limited number of sites
  • Useless for landlocked countries
  • High start up costs. The technology is still being developed
  • May be damaged by tropical storms

Wave: Using the motion of waves to generate electricity. /
  • It is a clean form of energy
  • It is a infinite resource
  • Ideal for island countries.
/
  • Again it can block shipping routes and interfere with animals
  • Again not suitable for landlocked countries
  • The strength of waves can vary
  • May be damaged by tropical storms
  • The technology is still being developed.

HEP (Hydroelectric power): Using the power of falling water in rivers to drive generators. At the moment dams have to be built to create HEP power.
/
  • It is a clean form of energy
  • It is finite as long as rivers are managed properly.
  • The built dam can also prevent flooding.
  • The reservoir behind the dam can be a store of water.
/
  • Only a limited number of suitable rivers
  • Can hamper navigation up and down river
  • Reservoirs may force resettlement
  • Migration patterns of animals maybe disrupted
  • Dams reduce the deposition of alluvium downstream
  • Dams can flood large areas of land.

Biofuels: The use of biological matter to create energy. It is a renewable form of energy, but because the mater is often burnt it still releases greenhouse gases.
/
  • It is a renewable form of energy as long as people replant crops.
  • It is cheap and the resources can be grown locally
/
  • It can still release greenhouse gases.
  • Areas can be deforested to grow crops for energy generation.
  • If crops are used for energy production it can lead to an increase in food prices.

Geothermal: Geothermal uses thermal energy from the earth to heat water. The water can be used as a source of hot water or the steam released can be used to drive turbines. /
  • It is a clean renewable form of energy.
  • It is a finite resource.
  • Can be used to heat water and generate electricity.
  • Geothermal energy can be created constantly and is not dependent on the weather.
/
  • Not every country has geothermal potential.
  • Installation and start up costs are expensive
  • Drilling can release harmful gases.
  • Geothermal activity can change which can make the production of energy harder

Fuelwood

Fuelwood is the most common source of energy for people living in LEDCs - it is estimated that about 40% of the world's population rely on fuelwood. Fuelwood is often the main source of energy because countries either can't afford to buy raw materials to produce energy, don't have the technology or money to build and operate powers stations and certainly don't have a national grid to distribute energy. Fuelwood has multiple functions, it can be used for cooking, heating and scaring away wild animals. Although using fuelwood is essential for many people it can cause environmental and social problems. Problems include:

  • Deforestation
  • Biodiversity loss (vegetation is removed and animals lose their home)
  • Desertification and reduced rainfall
  • Increased soil erosion and increased sandstorms
  • Increased time spent looking for wood
  • Children taken out of school to look for wood
  • Dangers posed by collecting wood (wild animals and criminals)
  • Dangers of breathing in smoke inside houses
  • Risk of fire within houses

Case Study – HEP - Three Gorges Dam

The Three Gorges Dam is the largest hydroelectric power station in the world. The dam is over 2km wide and it produces 22,500 MW of electricity. The HEP is located on the Yangtse River in Central China. China is the most populated country in the world and the Yangtse is the third longest river in the world. The site of the Three Gorges Dam was chosen over 15 other sites in China. Its location was picked for the following reasons:

  • As the third largest river in the world the river offered huge hydroelectric potential
  • The river valley was wide and flat making building easier
  • The bedrock was firm with limited cracks and fissures making it stronger
  • There was a small island in the river channel which made it easy to create a diversion channel during building
  • Despite large parts of China being seismically active, the area around the dam has not suffered any recent major quakes
  • There were towns and cities that needed to be relocated, but in communist China it was easy to purchase homes and relocate people e.g. Fengdu
  • China has a huge population (over 1.3 billion) so it was easy to mobilise workers

Case Study - Thermal Power Station (coal) - Ratcliffe-on-Soar, UK

A thermal power station is any power station that uses fossil fuels as its fuel. The Ratcliffe-on-Soar power station is located in the county of Nottinghamshire in central England. The power station was initially commissioned in 1968 and generates about 2,000 MW of electricity which can meet the needs of about 2 million people. The power station generates electricity using coal. The location of the power station was chosen because:

  • It is close to the River Trent so waster can be easily obtained for cooling
  • It is close the M1 motorway so raw materials can be transported to the power station easily.
  • When built it was close to the Derbyshire and Nottinghamshire coal mines - although most have now closed.
  • It was connected to the national grid
  • It was close to the major population centres of Derby, Leicester and Nottingham - supply of workers
  • It was located outside of any major cities to reduce protests (NIMBY)
  • It has a railway nearby to help with transportation of workers and materials
  • It was built on flat land (floodplain)

Case Study – Geothermal Energy – Iceland

Iceland is located along the Mid-Atlantic ridge, a divergent boundary where heat from the core of the Earth rises to the surface. The energy produced from this heat equates to around 30% of Iceland’s electricity production.

Cold water is pumped down to the igneous rock layers, where it is heated by contact with the hot rocks. The hot water is then piped up and the heat energy is converted to electricity.

Positive aspects:

  • emission-free
  • sustainable and potentially infinite
  • 3/4 of the population live near geothermal sources (in the south-west of Iceland, near Reykjavik)

Negative aspects:

  • high cost
  • obstruction that consumes land
  • visual pollution
  • regional limitations
  • may release dangerous underground gases

Water

How is Water Used?

Agriculture is by far the World's biggest user of water. Water is used for animals, but the majority is used for irrigation. The amount being used by agriculture is also increasing as the World's population increases and the demand for food increases. Household or domestic use in the next biggest user. The most water is usually used in toilets, but also washing machines and shower/baths use significant percentages. Industry and energy production also uses large percentages in manufacturing and cooling processes. The fourth biggest user is actually water lost through evaporation and leaks in reservoirs.

Groundwater: Groundwater is water stored under the ground.
Aquifer: Rocks that can hold water. Aquifers are called ''confined'' if they are surrounded and contained by aquitards and aquicludes. Unconfined are not contained by aquitards and aquicludes and instead their upper limit is the water table.
Water table: The boundary between saturated and unsaturated ground.

Economic water scarcity: This is when water is available, but for some reason it is inaccessible or unusable. This might because it is groundwater that is expensive to extract or that the cost of transporting it is too expensive or simply that the supply of water has become polluted.

Physical water scarcity: This is when there is not enough water available. The most common reason for this is low precipitation rates.
Water stress: This is when the demand for water exceeds the supply of water causing water shortages. Water shortages are known as droughts.

GROWING DEMAND / FALLING SUPPLY
  • Population Growth: As with many of the world's resources, they are coming under increasing pressure as the world's population grows. The world's population now stands at 7 billion, all of whom are placing increasing pressure on water resources as they develop and get richer.
  • Domestic Demand: The demand from households is not only increasing because there are more households in the world, but also because the amount of water they want is increasing with development. For example as peoples income increases and they move into permanent residences, they demand flush toilets, bath/showers, washing machines, dishwashers and green gardens, all of which use large amounts of water.
  • Agricultural Demand: As can be seen below, agricultural places by far the biggest demand on water. With a growing population, global warming and the movement in to less favourable agricultural regions, the demand from agriculture is only likely to increase in the future.
  • Industrial Demand: As the world's population grows and becomes richer our demand for industrial products grows. Many industrial products, particular things like metal making use huge quantities of water and place increasing demand on resources. Also mining for the raw materials used in manufacturing use large quantities of water.
  • Energy Production: Although HEP is the most obvious form of energy that uses water, this water is released into rivers once it has passed through the dam. Other types of energy that uses large amount of water for cooling e.g. coal and nuclear power, may pollute water or see it evaporated removing it from local use.
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  • Climate Change: Climate change is impacting the availability of water in many ways. Global warming maybe releasing freshwater from glaciers and ice shelves,but unfortunately much of it is running directly into the oceans. The subsequent rising sea levels are threatening many coastal freshwater wetlands as well as increasing the risk of saltwater intrusion into aquifers. Warmer temperatures are increasing the amount of evaporation from rivers and surfaces stores.
  • Groundwater Depletion: If water used unsustainable i.e. more is taken out than is being recharged then aquifers can suffer from salinisation and saltwater intrusion. If you increase the concentration of water it can become too salty for human to use. Also if you drain aquifers near coastal areas, then they can become full of saltwater, again making them useless.
  • Sewage: With rapid urbanisation taking place in many cities around the world, infrastructure often does not keep up with new arrivals. The growth of informal settlements without proper sewage treatment can mean that human waste is often pumped directly into water sources. However, this is not only a problem in LEDCs, in London the sewer system can not cope and an estimated 39 million tonnes of sewage are dumped in the River Thames.
  • Pollution: As the world's population grows so does the demand for agricultural and industrial products. Our thirst for agricultural products is increasing the use of fertilisers and pesticides which often run off into rivers and lakes or leach down to groundwater stores. Like wise our increasing demand for industrial and at times relaxed environmental regulations mean more chemicals and metals are being released into our water sources.
  • Political: In many countries or regions, water sources are shared e.g. the River Nile flows through eleven countries. At times some countries control large percentages of the shared resource, leading to shortages for other countries. Egypt and Sudan historically control much of the Nile's water and refuse to let other countries along the Nile use it.
  • Mismanagement: If water is not used sustainably or used inappropriately then water shortages can occur. One of the most famous examples is the Aral Sea. The Aral Sea is located on the border of Kazakhstan and Uzbekistan. Water was taken from the two rivers that fed the Aral Sea to irrigate the desert and grow cotton. Unfortunately so much water was needed to grow cotton in the desert, that no water reached the Aral Sea and it began to dry up.

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Problems Caused by Water Shortages and Water Pollution / Possible Solutions to Water Shortages and Water Pollution
  • Drought: If there are economic or physical water scarcity and water stress exists then drought can occur. Drought is below average supply of water over a prolonged period. Because drought is below average supply of water, even relatively wet country's like the UK can suffer from drought.
  • Crop Failure: If there is a shortage of water and farmers can not irrigate their crops then they begin to die.
  • Livestock Deaths: If livestock don't have enough water to drink they will begin to die.
  • Famine: If cops are failing and livestock are dieing then people will become undernourished and suffer from famine.
  • Groundwater Depletion (subsidence and saltwater intrusion): If aquifers begin to dry up or are used unsustainably, then the ground above can subside (collapse) or the aquifer can suffer from salinisation or saltwater intrusion.
  • Conflict: If there is a limited supply of water and water resources are shared conflict can arise. The ongoing border dispute between Israel and Palestine is often blamed on water shortages
  • Refugees: If there is drought and famine then people are forced to relocate or face death. Unfortunately many of the countries that suffer from drought and famine have poor neighbours so refugees will be arriving in countries that are least able to cope.
  • Disease: Dirty water can attract mosquitoes which can increase diseases like dengue and malaria. Dirty water can also cause the spread of diseases like hepatitis A and typhoid as well things like diarrhea.
  • Eutrophication: Run-off from farms containing fertiliser can lead to eutrophication. Eutrophication is the excess growth of algae causing water to not oxygenate properly or receive enough light. This can cause plants and animals to suffocate and die.
  • Biodiversity Loss: Dirty water and eutrophication can cause loss of biodiversity in wetland environments, but also just like humans can die of thirst and starvation, so can animals. Big animals like elephants which require large amounts of water often die in African droughts.
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  • Irrigation Projects: Countries that have regional shortages of water or variable rainfall can use irrigation systems to redistribute water and water the land.
  • Reduced Leakage: Leakage is a huge problem, especially in countries with old pipe networks. In the UK it is estimated that 460 million litres of water is lost everyday through leaks. In the UK there are targets for water companies to reduce leakages, unfortunately many companies are currently missing these targets.
  • Dam Construction: Dams are controversial because they can bring many disadvantages as well as advantages but if they are built sustainable they can create artificial stores that can collect water in rainy seasons and distribute during drier periods.
  • Water Metering: Charging people per unit of water used, rather than charging a flat fee can drastically reduce how and when they use water.
  • Construction of Wells: Many countries cannot afford to have piped water to every residence so wells become important in accessing groundwater supplies. As long as wells are used sustainably they can be a vital source of water in many LEDCs and arid countries.
  • International Cooperation: When water is shared, it is necessary to have sustainable policies to reduce the tragedy of the commons, when all countries or regions take water for their needs and forget about overall impacts.
  • Sewage Treatment: This is the removal of contaminants from waste water and household sewage. It requires physical, chemical and biological processes to remove all the contaminants and make safe.
  • Desalination: With the growing shortage of freshwater, attempts have been made to desalinate seawater more efficiently.
  • Conservation and Education: Residents and water users can be educated about basic conservation methods which can reduce water wastage. Basic conservation methods may include: half flush toilets, showering instead of bathing, watering the garden after sunset and recycling grey water (shower water, etc). to use in the garden

Case Study – The Aral Sea