energy resources - non-renewable energy resources

What are energy resources

• Fuels or resources which can be processed or harnessed to provide useful energy for humans

In what ways do energy resources vary

• Their accessibility and abundance

• The amount of useful energy derived

• The energy lost in transformations

• The energy required to harness, extract, process, and redistribute them

What are fuels

• Substances containing chemical energy that is released when oxidised, most commonly through combustion

Can fuels be reused once they are consumed

• No, once a fuel is used, it cannot be used again

Why does society need energy resources

• To facilitate many activities in industry and in homes

What are the two types of energy resources

• Renewable

• Non-renewable

What are non-renewable energy resources

• Sources that exist in limited deposits and cannot be replaced within timescales relevant to human lifetimes

Why are non-renewable resources considered finite

• They take very long geologic timescales to be replaced and are being used faster than they are being formed

What are examples of non-renewable energy resources

• Fossil fuels (coal, natural gas, petroleum)

• Uranium (for nuclear energy)

Are all reserves of non-renewable resources currently accessible

• No, some additional reserves may exist but are not currently accessible

What are the two categories of renewable energy

• Infinite resources (inexhaustible regardless of rate of use)

• Renewable but depletable resources (sustainable only if usage does not exceed replenishment rate)

What are examples of infinite renewable energy resources

• Solar energy

• Wind

• Tidal power

• Wave power

• Geothermal energy

What are examples of renewable resources that could be depleted

• Hydropower (running water)

• Wood

• Biofuel

What determines whether some renewable energy sources can be depleted

• If their rate of use exceeds their rate of replenishment

What are the two main types of energy resources

• Non-renewables

• Renewables

What are examples of non-renewable energy sources

• Fossil fuels and other non-renewable fuels

What fuels are classified as fossil fuels

• Coal

• Natural gas

• Petroleum.

What are examples of other non-renewable fuels (besides fossil fuels)

• Uranium (for nuclear energy)

What are the two categories of renewable energy resources

• Infinite energy resources

• Finite renewable resources

What are examples of infinite energy resources

• Solar

• Wind

• Tidal

• Wave

• Geothermal

What are examples of finite renewable resources

• Hydropower

• Wood

• Biofuels

What form of energy does coal use to create electricity

• Potential chemical energy

What is the efficiency of coal in creating electricity

• 25% – 30% efficient

What is a positive of coal as an energy resource in Australia

• Ample reserves, existing infrastructure, provides 85% of Australia’s electricity, and is one of Australia’s largest export commodities

How are fossil fuels like coal formed

• From organic matter accumulated in shallow sedimentary basins, compressed over millions of years through geologic processes

What types of coal exist as fossil fuels

• Lignite (brown coal) and anthracite (black coal)

How is coal usually mined in Australia

• In open-cut mines

Is coal renewable or non-renewable

• Non-renewable fossil fuel

What percentage does coal contribute to the enhanced greenhouse effect

• 45%

What environmental impacts are associated with coal mining

• Mining is physically destructive and releases methane

Why do coal power stations need large quantities of water

• For cooling

What kinds of air pollution are caused by coal power generation

• Sulfates and nitrates

How reliable is coal as an energy source

• Highly reliable

How much electricity does coal currently provide

• ~85% of Australia’s electricity and ~38% of the world’s electricity

How is energy produced from coal

• Coal is combusted in a furnace to create steam, which turns a turbine. The turbine drives a generator that produces an electrical current

How is the electricity from coal power stations distributed

• Sent along high-voltage, low-loss power lines and provided to housing and industry at appropriate levels

What are the economic aspects of coal power

• Expensive to establish but relatively low cost to run

How long are the estimated coal reserves expected to last

• Approximately 250–1000 years

How is coal formed

• From thick layers of plant matter altered by decay, heat, and pressure

Where are the largest coal reserves in Australia located

• Queensland, New South Wales, and the Latrobe Valley of Victoria

What happens to coal as you move down through the layers of formation

• Pressure and heat increase, which increases the heat content of the coal type

How does the energy content of oil compare to coal

• Oil has a higher energy content than coal

How does oil combustion compare to coal in terms of pollution

• Oil produces less pollution than coal during combustion

What products are formed from crude oil through distillation

• Bitumen

• Diesel

• Kerosene

• Petrol

• Other fuels/substances

Where are major oil reserves located in Australia

• Northwest Shelf of Western Australia and Bass Strait

How is crude oil processed

• In a refinery to produce fuels and other useful substances

What are the main uses of crude oil

• Transport, some heating, and industrial processes

How much of the crude oil reserves are estimated to remain

• Approximately a 50-year supply

What are the economic aspects of oil power/usage

• Expensive to establish but relatively low cost to run

How dependent is the world on crude oil

• Highly dependent; it currently provides most power for transport worldwide

How is crude oil formed

• Buried marine organic materials are transformed into petroleum products by intense pressure and heat in rock formations

Is crude oil renewable or non-renewable

• Non-renewable fossil fuel

What percentage does crude oil contribute to the enhanced greenhouse effect

• 35%

Where are natural gas reserves usually found

• Usually above oil deposits, though in Australia some may come from nearby coal beds

Where are major natural gas reserves in Australia

• Northwest Shelf of Western Australia and Bass Strait

What is natural gas primarily composed of

• Methane, with traces of ethane, propane, and butane

How is natural gas formed

• Fossil fuel formed over millions of years from organisms within swamps through geological processes

How is natural gas extracted

• Pumped from underground via a rig

What are the economic/infrastructure considerations for natural gas

• Pipelines are expensive, so gas is sometimes burnt off instead of used

How clean is natural gas combustion

• Quite clean; it produces no “other” pollutants

What are the economic aspects of natural gas

• Expensive to establish but relatively low cost to run

How much of the world’s electricity is currently provided by natural gas

• Approximately 17%

What is the efficiency of natural gas

• 30% for electricity generation; 90% for heating

How much of the natural gas reserves are estimated to remain

• Approximately a 70-year supply

Is natural gas renewable or non-renewable

• Non-renewable fossil fuel

How much does natural gas contribute to the enhanced greenhouse effect

• 18%

How does natural gas compare in abundance and cost to other energy sources

• Less abundant and higher cost than coal, but relatively low cost compared to renewables and uranium

What is coal seam gas (CSG)

• Natural gas that collects in underground coal seams and bonds to the surface of coal particles

What keeps CSG attached to coal particles

• The pressure of water in the coal seams, which keeps the gas as a thin film on the coal surface

At what depths are coal seams containing CSG typically found

• Generally at depths of 300–1000 meters

Where are Australia’s largest coal seam gas reserves located

• Particularly along the east coast

What is fracking

• The process of drilling into the earth and using a high-pressure liquid mix of water and chemicals on sedimentary rock to release gases stored inside. The term refers to the fracturing of the rock

Why is fracking controversial

Environmental concerns include:

• Huge water usage and transportation

• Potential release of harmful chemicals

• Threat of tremors and earthquakes

Why is coal seam gas considered an unconventional gas

• Because it requires specialized extraction methods, such as hydraulic fracturing (fracking)

How does hydraulic fracturing (fracking) extract coal seam gas

• High-pressure injections of sand, water, and chemicals are used to fracture the coal seam, allowing gas to flow to the surface

What are the major environmental concerns with fracking

• Fugitive gases potentially contaminating water sources

• Possible seismic activity and tremors

Which Australian states first banned coal seam gas and fracking

• Victoria in 2016, followed by Tasmania

Is uranium a fossil fuel

• No, uranium is a non-renewable energy source but not a fossil fuel

How is uranium used to produce electricity

• Uranium is used in nuclear reactors to produce heat, which generates electricity

What process releases energy in a nuclear reactor

• Nuclear fission chain reactions

How is a fission reaction initiated

• By a neutron striking the nucleus of a large atom, causing it to split into smaller nuclei

What happens when the nucleus splits during fission

• Energy and additional neutrons are released, which can strike other nuclei and continue the chain reaction

Which uranium isotope can undergo nuclear fission

• Uranium-235

What happens to mass during a nuclear fission reaction

• A small amount of mass is converted into energy

How efficient is nuclear energy as a fuel source

• Highly efficient, with a total energy efficiency of approximately 90%

What is nuclear fusion

• A reaction where energy is released when two atoms are forced together

Where does fusion occur naturally

• In the Sun, producing solar energy

What is a human-made example of fusion

• The hydrogen bomb

Which isotopes are used as fuel in fusion power

• Heavy hydrogen isotopes deuterium (hydrogen-2) and tritium (hydrogen-3)

Why is fusion considered an attractive future energy source

• It is clean, sustainable, and the fuel is so abundant it could meet the world’s electricity needs for millions of years

Has controlled fusion been achieved on a large scale

• No, controlled fusion has only occurred on a small scale in laboratories, and full-sized reactors are not yet feasible