Energy Sources (Cambridge (CIE) IGCSE Physics)

False.

Solar farms need to be large-scale to produce significant amounts of electricity.

Fossil fuels are natural resources formed over millions of years from the remains of plants and animals.

The three main fossil fuels are:

• coal

• oil

• natural gas (methane)

False.

Burning fossil fuels produces carbon dioxide which is a greenhouse gas that contributes to global warming. But other harmful gases are also released in the combustion of fossil fuels, such as sulphur dioxide which causes acid rain.

The disadvantages of using fossil fuels include:

• non-renewable (so will run out)

• produce carbon dioxide which contributes to global warming

• produce sulphur dioxide which causes acid rain

The main uses of fossil fuels are transportation, electricity generation, and heating in homes and industries.

True.

It takes millions of years for fossil fuels to form. This is why they are considered a non-renewable energy resource.

Energy is transferred from the chemical store of the fossil fuel during combustion. This energy originally came from sunlight and was transferred to plants and animals through photosynthesis.

Biofuels are produced from plant matter, such as crops, which undergo processes like fermentation or distillation to extract ethanol or methane for use as alternative fuels to fossil fuels.

The main advantages of biofuels are:

• renewable

• carbon neutral

True.

Nuclear power stations do not release pollution into the atmosphere during normal operation.

Nuclear fuel refers to materials, such as uranium, used in nuclear reactors to release energy in nuclear fission reactions.

Nuclear power stations generate electricity by using the energy released in nuclear fission reactions to heat water to produce steam. The steam then turns turbines connected to generators, which produce electricity.

Nuclear fuel is a non-renewable resource because there is a finite supply of uranium ore found in the ground.

Wave and tide power harnesses the energy from the rise and fall of waves or tides to generate electricity, typically using turbines.

False.

Wave and tidal power do not produce pollution.

The primary advantages of wave and tide power are that they are renewable energy resources that produce no pollution.

Wave and tidal power stations generate electricity by utilising the motion of waves or tides to turn turbines, which then generate electricity through electromagnetic induction.

False.

Tidal barrages are small systems that produce small amounts of electricity.

The main purpose of underwater turbines in wave and tide power systems is to transfer energy from the kinetic store of the moving water to the kinetic store of the turbines, which turn generators that generate electricity.

Hydroelectric dams are structures built across rivers to store water at a height in reservoirs. The water can be released, flowing over a turbine that turns a generator that generates electricity.

True.

Hydroelectric dams can release significant amounts of greenhouse gases due to the decomposition of organic matter in flooded areas, or due to the fuels used to pump the water back up to the reservoir.

The main disadvantage of hydroelectric dams is that they require valleys to be flooded. This results in the destruction of habitats, towns, and villages.

The main advantage of hydroelectric dams is their ability to respond to electricity demand quickly and reliably.

Geothermal energy is energy stored in the thermal store of rocks beneath the Earth's surface from tectonic heating. The hot rocks are used to heat water that can be used as a hot water supply and to produce steam to turn turbines for electricity generation.

False.

Geothermal energy is considered a renewable resource.

The primary advantage of geothermal energy is its reliability and renewability. It offers a consistent source of heating and electricity production.

The main disadvantage of geothermal energy is the limited availability of suitable locations for large-scale electricity production.

False.

Geothermal power stations are typically small compared to nuclear or fossil fuel power stations due to the limited availability of suitable geothermal sites.

Geothermal energy generates electricity by heating water and generating steam using the hot rocks beneath the Earth's surface, which drives turbines to produce electricity.

Geothermal energy is a renewable energy resource. This means it can be replenished naturally and is sustainable over the long term.

The main advantage of geothermal power stations is their reliability as a source of energy. They provide a consistent and uninterrupted supply of heat and electricity in suitable regions.

Nuclear fusion is the process by which small nuclei, such as hydrogen, combine to form larger nuclei, releasing a massive amount of energy in the process.

False.

The Sun's energy is released through nuclear fusion reactions, where hydrogen nuclei combine to form helium nuclei, releasing massive amounts of energy in the process.

The primary advantage of nuclear fusion is its potential to provide virtually limitless energy with minimal environmental impact. It generates no greenhouse gases and produces minimal radioactive waste.

The main challenge associated with nuclear fusion is the requirement of extremely high temperatures and pressures to initiate and sustain fusion reactions, similar to those found in the core of stars.

False.

Fusion reactors are still in the experimental stage, and while progress is being made, no fusion reactor has yet achieved sustained net energy production for commercial use.

Nuclear fusion involves the fusion of small nuclei, such as hydrogen, to form larger nuclei, while nuclear fission involves the splitting of larger nuclei, such as uranium, into smaller nuclei.

Scientists are researching methods to sustain fusion reactions at lower temperatures and pressures. This will make fusion more practical for energy generation on Earth.

False.

Currently, fusion reactions require nearly as much energy as they release. Ongoing research aims to achieve sustained net energy production in fusion reactions.

Successful fusion energy could revolutionise global energy production, providing a sustainable, carbon-free source of electricity with virtually unlimited fuel availability.