Key Terms

This resource provides explanations of the key concepts encountered when exploring Future Fuels – the ‘basics’ that every student should understand.

Page links to Key Term definitions

1. Sun – the source of most of Earth’s energy
2. Conservation of energy
3. Energy efficiency
4. Renewable and non-renewable energy sources
5. Fossil fuel
6. Carbon dioxide emission
7. Solar energy budget
8. Petroleum
9. Radiation

List of Key Term definitions

1. 

   1. Sun – the source of most of Earth’s energy

   With the exception of nuclear energy, the Sun is the source of all other energy on Earth. The water cycle and winds are both driven by the Sun, and bio and fossil fuels are dependent on photosynthesis – plants harnessing the Sun’s energy to make sugars.

2. 

   2. Conservation of energy

   The law of conservation states that energy cannot be made or destroyed. This means that the amount of energy in a system is constant – it can be transformed from one form into another (for example, electrical energy to heat energy) but will never be destroyed.

3. 

   3. Energy efficiency

   When energy changes form (through transformation or transfer), there will always be some energy that is lost to the environment (such as heat). How well we are able to use energy is described as the efficiency – the more energy lost to the environment, the less efficient the energy transfer.

4. 

   4. Renewable and non-renewable energy sources

   Renewable energy comes from a source that we can either reuse (such as water) or replace (such as trees). Conversely, non-renewable energy comes from a source that cannot be reused or replaced (or not for millions of years). Uranium used in nuclear power and fossil fuels such as oil are both examples of non-renewable energy sources.

5. 

   5. Fossil fuel

   Fossil fuels (coal, oil and natural gas) were formed from animals and plants that lived hundred of millions of years ago. When an animal or plant died, under the right conditions, its body was compressed to form fossil fuels. The energy present in the fossil was trapped, and humans now use this energy when they burn fossil fuels. Fossil fuels are non-renewable because it takes millions of years for the process to occur, and we will one day run out of coal, oil and natural gas.

6. 

   6. Carbon dioxide emission

   CO₂ emission is the amount of carbon dioxide (CO₂) released into the atmosphere.

7. 

   7. Solar energy budget

   The solar energy budget describes the incoming solar radiation (short wave) and outgoing radiation (long wave) from Earth. On average, 30 percent of the incoming solar radiation is reflected back to space by clouds and does not contribute to any heating on Earth. Of the remaining 70 percent, 19 percent is absorbed by the atmosphere (mainly through water vapour) and the remaining 51 percent is absorbed by land and oceans combined. This 51 percent of absorbed energy is then re-radiated by land and sea and, of that, 45 percent is temporarily absorbed in the atmosphere adding to the earlier 19 percent held from the incoming radiation. The remaining six percent still ‘owing’ radiates as infrared rays directly from the ground to outer space.

8. 

   8. Petroleum

   Petroleum, petrol and gasoline are all common names for the same product – the liquid fuel we use to run our cars. Petroleum can also mean crude oil and oil products (such as the oil we use to lubricate our engines).

9. 

   9. Radiation

   Radiation describes the emission of rays or waves of energy. When we feel heat, we are feeling the energy waves from the hot object radiating towards us. Radioactive substances can emit streams of particles or electromagnetic waves as a result of nuclear decay.