ESS - Unit 7 Notes
7.1 – Energy Choices and Security
Significant Ideas:
· There is a range of different energy sources available to societies that vary in their
sustainability, availability, cost and socio-political implications.
· The choice of energy sources is controversial and complex. Energy security is an important
factor in making energy choices.
Knowledge and Understanding:
· Fossil fuels contribute to the majority of humankind’s energy supply, and they vary widely in
the impacts of their production and their emissions; their use is expected to increase to meet
global energy demand.
· Sources of energy with lower carbon dioxide emissions than fossil fuels include renewable
energy (solar, biomass, hydropower, wind, wave, tidal and geothermal) and their use is
expected to increase. Nuclear power is a low-carbon low-emission non-renewable resource
but is controversial due to the radioactive waste it produces, and possible disasters.
· Energy security depends on adequate, reliable and affordable supply of energy that provides
a degree of independence. An inequitable availability and uneven distributions of energy
sources may lead to conflict.
· The energy choices adopted by a society may be influenced by availability; sustainability;
scientific and technological developments; cultural attitudes; and political, economic and
environmental factors. These in turn affect energy security and independence.
· Improvements in energy efficiencies and energy conservation can limit growth in energy
demand and contribute to energy security.
Energy Resources
Energy resources are usually divided into two main types. These are renewable energy
resources and non-renewable energy resources. It takes about the same amount of time to
replace renewable energy resources as it takes to extract them. A good example is biofuels.
These can be renewed through photosynthesis. Replenishable energy resources may rely on
solar energy in order to be restored, such as hydroelectric power and wind power. It takes a
much longer time to replace non-renewable energy resources than it takes to extract them. Oil
and coal are good examples of non-renewable energy resources. They are also called fossil
fuels. This is because they are formed out of the remains of living organisms.
, Cost of Energy Resources
The costs of energy resources may come from extraction, production, transport, storage, and
utilization. Some energy sources have a high set-up cost but a low production cost. Solar
energy has high set-up costs but low production costs.
Some energy sources have low set-up costs but high production costs. Peat-burning has low
set-up costs but high production costs. Biofuel is a renewable energy resource. It has relatively
low set-up costs, but production costs may be high. This is because it takes lots of effort to cut
and carry the biofuel back to the house or farm.
Fossil fuels are a form of non-renewable energy resource. It takes a huge amount of time for
them to form when compared to the amount of time it takes to extract them. Although large
reserves still exist, stocks are being reduced.
Hydroelectric energy is a replenishable energy resource. It depends on solar energy for its
renewal. It has high set-up costs but low production costs. How effective hydroelectric energy is
depends highly on where it is located. It requires a plentiful supply of water.
Comparing Two Contrasting Energy Sources
Oil is a non-renewable energy source. Hydroelectric power is a replenishable energy source.
Replenishable energy sources are renewable.
Advantages of Oil Disadvantages of Oil
It is a very efficient source of energy It is a finite resource and will run out
Can be used as fuel and to produce Burning oil releases carbon dioxide, which
electricity is a greenhouse gas.
It is relatively cheap Oil spills damage ecosystems.
7.1 – Energy Choices and Security
Significant Ideas:
· There is a range of different energy sources available to societies that vary in their
sustainability, availability, cost and socio-political implications.
· The choice of energy sources is controversial and complex. Energy security is an important
factor in making energy choices.
Knowledge and Understanding:
· Fossil fuels contribute to the majority of humankind’s energy supply, and they vary widely in
the impacts of their production and their emissions; their use is expected to increase to meet
global energy demand.
· Sources of energy with lower carbon dioxide emissions than fossil fuels include renewable
energy (solar, biomass, hydropower, wind, wave, tidal and geothermal) and their use is
expected to increase. Nuclear power is a low-carbon low-emission non-renewable resource
but is controversial due to the radioactive waste it produces, and possible disasters.
· Energy security depends on adequate, reliable and affordable supply of energy that provides
a degree of independence. An inequitable availability and uneven distributions of energy
sources may lead to conflict.
· The energy choices adopted by a society may be influenced by availability; sustainability;
scientific and technological developments; cultural attitudes; and political, economic and
environmental factors. These in turn affect energy security and independence.
· Improvements in energy efficiencies and energy conservation can limit growth in energy
demand and contribute to energy security.
Energy Resources
Energy resources are usually divided into two main types. These are renewable energy
resources and non-renewable energy resources. It takes about the same amount of time to
replace renewable energy resources as it takes to extract them. A good example is biofuels.
These can be renewed through photosynthesis. Replenishable energy resources may rely on
solar energy in order to be restored, such as hydroelectric power and wind power. It takes a
much longer time to replace non-renewable energy resources than it takes to extract them. Oil
and coal are good examples of non-renewable energy resources. They are also called fossil
fuels. This is because they are formed out of the remains of living organisms.
, Cost of Energy Resources
The costs of energy resources may come from extraction, production, transport, storage, and
utilization. Some energy sources have a high set-up cost but a low production cost. Solar
energy has high set-up costs but low production costs.
Some energy sources have low set-up costs but high production costs. Peat-burning has low
set-up costs but high production costs. Biofuel is a renewable energy resource. It has relatively
low set-up costs, but production costs may be high. This is because it takes lots of effort to cut
and carry the biofuel back to the house or farm.
Fossil fuels are a form of non-renewable energy resource. It takes a huge amount of time for
them to form when compared to the amount of time it takes to extract them. Although large
reserves still exist, stocks are being reduced.
Hydroelectric energy is a replenishable energy resource. It depends on solar energy for its
renewal. It has high set-up costs but low production costs. How effective hydroelectric energy is
depends highly on where it is located. It requires a plentiful supply of water.
Comparing Two Contrasting Energy Sources
Oil is a non-renewable energy source. Hydroelectric power is a replenishable energy source.
Replenishable energy sources are renewable.
Advantages of Oil Disadvantages of Oil
It is a very efficient source of energy It is a finite resource and will run out
Can be used as fuel and to produce Burning oil releases carbon dioxide, which
electricity is a greenhouse gas.
It is relatively cheap Oil spills damage ecosystems.
