Term
| What is an energy source? |
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Definition
| An energy source (sometimes called an energy resource) is a natural system (such as a waterfall) or store of energy (such as fuel) that we can use to make electricity. |
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Term
| What is the most versatile form of energy? |
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Definition
| The most versatile form of energy is electricity. We have devised many gadgets and machines that run on electrical power to do useful work for us and we also have developed many that simply amuse and entertain us. They take electrical energy and turn it into other forms (see energy types) - forms that we need! It works so well to satisfy our need for help in performing tasks that our lives would be very different without it. Ask an elderly relative what life was like without electricity and/or imagine what it would be like if suddenly we all had no electrical power. Life would be much harder and a lot less fun! |
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Term
| How do we classify energy resources? |
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Definition
| Into renewable and non-renewable energy resources |
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Term
| What are re-newable energy resources? |
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Definition
| Renewable energy resources are the oldest, cleanest and in most cases the most efficient forms of energy humans have at their disposal. They will never run out (well not until our Sun burns out - and we will probably be extinct by then!) and do not pollute the environment by emitting gases that cause global warming effects or acid rain, nor do they produce radioactive waste.
They are not 'resusable' they are constantly being replenished. |
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Term
| What is the problem with non-renewable resources? |
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Definition
| The pollution from non-renewables is causing a lot of problems for our planet, but they are well established as energy resources and to suddenly stop using them would cause social problems for countries (eg. closing a coal mine would put lots of people out of work!). In the long term it is important that we decrease our use of non-renewable and increase the use of renewable energy sources. |
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Term
| What are non-renewable resources? |
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Definition
| Non-renewable resources (fossil fuels and nuclear power) will not be naturally replaced. Nuclear power uses Uranium. This was in the rocks of the planet when it was formed - we cannot get any from anywhere else! The nuclear industry has tried to put forward the case that it is renewable as the process that splits the Uranium 235 to make nuclear (or atomic) power also causes the Uranium-238 present to change into Plutonium and that can be used as a nuclear fuel too. But nuclear power is not classed as renewable - it is a non-renewable source. |
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Term
| Why will fossil fuels 'run out'? |
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Definition
| Fossil fuels are classed as non-renewable but coal is being remade even as you read this! So, as the fossil fuels will be replaced you might argue they should be classed as renewable. They are the fossilised remains of plants and animals, so they could form new fossil fuels. That is true... but to be a fossil you must be more than 10,000 years old ... so even a leaf would take that long to turn into pure carbonised fossil material - a whole tree (needed for a decent coal seam) would take a lot longer! (7,000 years ago Britain was in the Stone age and the earliest pyramids were thought to be built about 5.000 years ago... so does that put it into perspective for you?). We will be long extinct before the fossil fuels are replaced. |
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Term
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Definition
| Billions of photons of electromagnetic energy leave the Sun and hit our Earth every second. The energy can be used directly by us to get electrical energy from sunlight in photo-voltaic cells [image]
and in solar heating panels to get heat energy from the Sun. panels.[image]This process is constantly happening and so is a renewable resource.
Click here for more details |
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Term
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Definition
| Using once living matter used as a fuel - wood, dung, seeds, plant oil etc. By photosynthesis the Sun's energy combines water and carbon dioxide to make plant material (a chemical energy store)- this is eaten by animals to make animal material (another chemical energy store). These can be burned to release the chemical energy stored. Camel dung is an excellent fuel - used by nomads in the desert![image]
This process is repeating over a small time scale and so is a renewable resource. It originally comes from the Sun's energy. Click here for more details |
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Definition
| Uneven heating of the atmosphere by the Sun causes pressure differences that result in movement of air masses. The kinetic energy of the wind is used to turn sails of wind mills and aerogenerators. [image]
This process is constantly happening and so is a renewable resource. It originally comes from the Sun's energy. Click here for more details |
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Term
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Definition
| The wind (from the sun because of uneven heating of the atmosphere causing pressure differences that cause air masses to move) blows on the water to makes waves. 'Ducks' and OWCs can be used to convert the kinetic energy to electricity. One of the ways to capture some of this energy is the oscillating water column (OWC). When waves hit an OWC, the air inside is compressed and forced through air turbines - these turn the generator and make electricity by electromagnetic induction. [image]
"Salter Ducks" are floating canisters that are connected in a chain of about 25 across the sea. Each float is called a 'Duck' because it bobs up and down! It about the size of a double decker bus! It weighs about 300-tonnes and is designed to drive a generator from the motion of bobbing up and down on waves like a duck. It. This system has the potential to capture a lot of energy.
[image]
This process is constantly happening and so is a renewable resource. It originally comes from the Sun's energy. Click here for more details |
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Term
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Definition
| Hydro-Electric Power. The Sun powers the water cycle and HEP uses water falling under gravity (waterfalls and fast flowing rivers) to turn turbines to make electricity. The Sun powers the water cycle allowing water to gain gravitational potential energy by being lifted up into the clouds and falling on high places like mountain tops This process is constantly happening and so is a renewable resource. It originally comes from the Sun's energy. Click here for more details |
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Term
| What is geothermal energy. |
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Definition
| Hot rocks within the earth heat underground streams. Radioactive materials release heat energy when they decay. This is one of the main reasons why the Earth is still hot inside.The rocks get hot from the radioactive decay. This is NOT energyy from the sun. It is nuclear energy from the atoms that make up the Earth's core that is released when radioactive decay occurs. This process is continually happening so the energy will not run out for a very long time. It is therefore renewable. Click here for more details |
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Definition
| [image]
The gravitational pull of the moon (and the Sun - but its effect is smaller as it is so far away!) on the oceans causes the tides. The movement of the water within river mouths (estuaries) is made to flow through sluice gates in a dam and thereby used to turn turbines to make electricity. This process is constantly happening and so is a renewable resource. It originally comes from the graviational forces between the seas and the moon.
[image]
Click here for more details |
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Term
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Definition
| Uranium-235 atoms split to release energy by the process of fission. They are a store of nuclear (or atomic) energy. Heat energy is produced when the atom nucleus splits. The heat is used to boil water and the pressure of the steam produced is used to turn turbines to make electricity. This is non-renewable as there is a limited supply of Uranium in the Earth's crust and we will one day run out! Click here for more details |
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Term
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Definition
| Coal, Oil and natural gas (methane). Fossil fuesl are highly compressed, ancient, once living matter (prehistoric biomass!) - a very concentrated form of chemical energy. Originally made by photosynthesis from the Sun's energy and then subjected to high pressure and/or temperature over a long time period to fossilize the biomass. Will run out as it is limited in quantity and takes such a long time to form. Fossil fuels are burnt in power stations. The heat given off is used to boil water and the pressure of the steam produced is used to turn turbines to make electricity. Click here for more details |
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