Summary of topic 7.1

Summary of topic 7.1

• 1.
  Topic 7.1 Climate changeand energy production 7.1 Energy choices and security
• 2.
  Range of EnergyResources • Renewable – Solar – Hydroelectric – Geothermal – Biomass – Tidal – Wave • Non-renewable – Coal – Gas – Oil – Nuclear Macro-scale (country-wide schemes contributing to the national grid) Micro-scale (domestic or within small communities) http://www.youtube.com/watch?v=Gz_L6KuqvFI
• 3.
  Range of EnergyResources • In 2004, global energy production was 500 exajoules (1 exajoule = 1 x 1018 J) • Approximately 80% of this was derived from fossil fuels • Fossil fuels provided the basis of the industrial revolution (initially coal in Britain) and have been depended on ever since • Oil is (was?) plentiful, portable and readily distilled into fractions such as petroleum and kerosene • The advent of the combustion engine has cemented our dependence on oil • Crude oil is extracted in combination with natural gas • The effects of fossil fuels on the environment were not really considered until recently
• 4.
  Range of EnergyResources
• 5.
  Energy Consumption
• 6.
  Energy Consumption • Percapita energy use in MEDCs is much higher than LEDCs • The economies of MEDCs are based on high technology, high energy use, high fossil fuel use • The economies of LEDCs traditionally have less available technology, greater dependence on natural resources (wood and biomass combustion), lower use of fossil fuels http://www.youtube.com/watch?v=9qFKqDnGX0g
• 7.
  Energy Security • Thisdepends on supplies of energy that are: – Adequate – Reliable – Affordable – Provide a degree of independence • Security in energy is also helped by increasing the efficiency of energy use
• 8.
  Energy Consumption
• 9.
  Energy Consumption
• 10.
  Energy Consumption • Non-renewableresources are generally cheaper than renewables • Natural gas is cheap, relatively plentiful, can be burned without refining, and is fairly clean (compared to other fossil fuels) • Non-renewables generally have high capital costs, may be in the experimental stage and may be dependent on unreliable natural phenomena (wind, waves, sun etc.) • The use of renewables will increase in the future as fossil fuels become depleted and less accessible – prices and taxes on polluting fuels will increase
• 11.
  Renewable Resources • Donot usually release greenhouse gases (the exception is biofuels – which are in any case carbon neutral) • Do not release NOx and SOx • Small ecological footprint (biofuel cultivation is an exception) • Generally expensive to exploit compared to fossil fuels (high capital and maintenance costs) • Many technologies are still in the developmental stage • Locations may be limited due to politics, local conditions and reluctance of local people (e.g. to live near wind turbines) Advantages Disadvantages
• 12.
  Hydroelectric Power • Reliablesource of energy which can be switched on and off when needed • Do not release NOx and SOx or greenhouse gases • Creates artificial lakes which are used as recreational areas and reservoirs • Cheap to run and maintain once built • High capital costs • Large areas must be flooded, displacing populations, destroying farmland and altering downstream ecosystems • Increased downstream erosion rates Advantages Disadvantages
• 13.
  Tidal Power • Reliablesource of energy • Do not release NOx and SOx or greenhouse gases • Cheap to run and maintain once built • High capital costs • Locations are limited by tidal range and shape of the coastline • May interfere with navigation routes and wildlife Advantages Disadvantages
• 14.
  Solar Power • Reliablesource of energy • Do not release NOx and SOx or greenhouse gases • Cheap to run • High capital costs and still being developed • Locations are limited by availability of sunlight • Storage of energy requires use of expensive batteries which may be polluting when disposed of • May be expensive to maintain if things go wrong • Components are expensive and their extraction may cause environmental damage Advantages Disadvantages
• 15.
  Wind Power • Reliablesource of energy • Do not release NOx and SOx or greenhouse gases • Cheap to run and maintain (there is little to go wrong with a wind turbine) • High capital costs and still being developed • Locations are limited by availability of wind • In many places there is reluctance to live near wind turbines due to noise and perception that they spoil landscapes • May have effects on wildlife, especially birds Advantages Disadvantages
• 16.
  Biofuels • Carbon neutral •Do not release NOx and SOx • Do not require existing technologies to be replaced for their use (i.e. the internal combustion engine) • As portable as existing fossil fuels • Produce greenhouse gases when combusted • Large ecological footprint • Monoculture – therefore often displace farmland and poor communities (also affecting food prices) or destroy virgin forest or other ecosystems • Pesticide use represents further risk to the environment Advantages Disadvantages
• 17.
  Combustion of WasteMaterials • Free resource (readily available and represents no depletion of natural capital – although waste should be minimised) • May be burned directly or used as a source of methane from decomposition • Burning of methane reduces the effect of a potent greenhouse gas that would otherwise enter the atmosphere • Reduces pressure on landfill sites and waste transportation • Produces greenhouse gases when combusted • Results in the production of other harmful pollutants, especially dioxins Advantages Disadvantages Renewable or non-renewable resource?
• 18.
  Geothermal Energy • Freeand readily available resource • Does not need to be converted to other forms of energy if used for heating • May also be used to generate electricity • Simple technology with low capital and maintenance costs • Does not result in any form of pollution or have any visible effects on the landscape if used domestically • Generally restricted to volcanic areas such as Iceland Advantages Disadvantages
• 19.
  Fossil Fuels • Cheapand plentiful (at least in the past) • Existing technology for extraction and use • Existing technology to control pollution (to some extent) • Generally portable and can be delivered over long distances (coal is perhaps an exception) • No other sources are able to generate as much energy at the present time • Polluting (CO2, NOx, SOx) • Unsustainable (by definition, supplies are limited) • As resources diminish it will become more difficult and dangerous to extract them • Accidents cause severe damage to ecosystems • Open-cast mining causes habitat destruction on large scales Advantages Disadvantages
• 20.
  Nuclear Power • Doesnot produce greenhouse gases • Existing technology • Produces large quantities of energy • Extremely energy efficient (1kg of uranium produces 20000 x more energy than 1kg of coal) • By-products may remain radioactive for many thousands of years (there are unresolved problems of waste disposal) • Radiation exposure results in death, severe forms of cancer and DNA damage (genetic effects are heritable) • Accidents may cause severe damage to human health and ecosystems (there is high associated risk) • Uranium is a scarce and non- renewable resource • Planning is long and complex Advantages Disadvantages
• 21.
  Factors Affecting Choiceof Resource MEDCs have much higher energy demands than LEDCs http://www.youtube.com/watch?v=KtWoPZluI2E
• 22.
  Factors Affecting Choiceof Resource • GDP has a large say in which resources can be used or developed • Historical basis (fossil fuel dependence is a hangover from the industrial revolution, especially in those countries that participated in it) • Greater car use in MEDCs leads to greater dependence on petroleum • Low uptake of nuclear power in MEDCs due to perceived risk and problems of waste disposal (France is an exception with 78% of electricity generation from nuclear sources; USA 20%) • Fossil fuels are often a cheaper option due to existing, readily available, large-scale technology • Humans are resistant to large-scale change especially when costs are stable (recession can change this perception) • There is some reluctance to change to renewables due to the perception that they can spoil natural landscapes • There is increasing awareness of the environmental damage caused by fossil fuel use which is leading to greater acceptance of renewable resource use • Choice of resources is largely driven by government policy
• 23.
  Questions 1. Outline therange of energy resources available 2. Evaluate the advantages and disadvantages of two named renewable resources and two named non-renewables 3. Discuss the factors that affect the choice of energy resources by MEDCs and LEDCs