7.1 Energy choices and security

Energy security

The uninterrupted availability of energy sources at an affordable price. Various aspects must be considered for a country to maintain energy security.

Choices of energy

A countries decision on what energy source to use.

• Depends on various factors such as the availability of supply, technological developments, politics, economics, cultural attitudes, sustainability and environmental consdierations.

USA shale oil

OIl held tightly in rocks that has previously not been extracted but is now extracted due to advances in technology such as fracking.

Fracking

The process of injecting liquid at high pressures into rick to force open fissues and extract oil or gas.

• Allowed for the US to go from 600k barrels of oil a day to 3.5 million.

Non renewable sources of energy

Energy sources that will run out in time such as fossil fuels

• Coal will run out in 230 years

• Gas will run out in 170 years

• Oil will run out in 100 years

Renewable sources of energy

Energy sources that are sustainable and not depleted when used such as wind, and solar energy. Not used as much as fossil fuels and also has its own limitations.

Coal

A non renewable fuel source made of fossilized plants which is mined from rocks and burned to produce heat or electricity through creating steam.

• Benefits: Alot of it still exists, doesn’t need to be processed, cheap to mine

• Disadvantages: Non renewable, contains sulphur which creates sulphur dioxide, destroys landscape, causes lung diseases

Oil

A non renewable fuel made of fossilized plant matter which is extracted by oil wells.

• Benefits: Many uses in industry, cheap to mine and convert to energy.

• Disadvantages: Limited supply, gives off carbon dioxide when burned, oil spills are possible.

Natural gas

A non renewable fuel made of hydrogarbons and methane gas which exists between rocks. Used in various household applications.

• Benefits: Lots of energy from burning it, cheap, cleaner fuel than coal and oil.

• Disadvantages: Limited supply, gives off carbon dioxide when burned.

Nuclear fission

An energy source which uses uranium in a nuclear reactor which bombards it with neutrons, releasing alot of energy as it breaks down.

• Benefits: Cheap to make, produces alot of energy from small mass of uranium, no pollutants released.

• Disadvantages: Nuclear waste highly toxic, storage of waste difficult, accidental leakage of radioactive material would be disasterous, uranium can be used in weapons.

Hydroelectric power

Energy source where the movement of water through rivers, lakes and dams move turvines that generates electricity.

• Benefits: Pretty safe, creates water reserves, high energy output.

• Disadvantages: Expensive to build, can cause flooding, dams can impact hydrology, can cause sediment buildup which reduces sand deposits.

Biomass

Fuel source made of decaying organic plant matter or animal waste to produce methane or burned directly. Can be processed further to produce biofuels.

• Advantages: Cheap to obtain, long term sustainable energy source if crops grown.

• Disadvantages: Can lead to starvation if food crops are grown just to produce fuel, gives off atmospheric pollutants when burned.

Wood

Fuel source from chopping down trees.

• Benefits: Cheap fuel source, sustainable energy source.

• Disadvantages: Not alot of energy released for amount of mass, cost of transportation high, releases particulates when burned.

Concentrated solar power

Energy source where mirrors focus solar energy on one point where heat energy generated drives a steam turbine to make electricity.

• Benefits: Solar energy is renewable

• Disadvantages: Needs to be built in trophics

Passive solar power

Energy source which puts panels to capture and store heat

• Benefits: Low cost

• Disadvantages: Requires architects to build effective designs

Wind power

Energy source which uses wind turbines that uses winds to push them, creating energy.

• Benefits: Clean energy supply, requires little maintenance

• Disadvantages: Needs wind, wind farms expensive to build, might kill birds, destroys countryside visually.

Tidal energy

Energy source where the in and out motion of the tides drives turbines

• Benefits: Can create alot of energy, good for island countries, can prevent flooding

• Disadvantages: Barrage construction expensive, negative impact on wildlife

Geothermal energy

Energy source that takes advantage of the heat under the earth in volcanic regions. Pushes cold water which turns into steam to power turbines.

• Benefits: Infinite energy supply

Disadvantages: Expensive to set up, only works in areas of volcanic activity, might be gases when setting up.

Biofuel

Energy source that makes fuel out of plants such as sugarcane and corn.

• Benefits: May become viable alternate to fossil fuels in the future.

• Disadvantages: May actually release more carbon in the atmosphere due to the amount of crops needed to produce biofuel.