New! Revision puzzle for energy sources

An energy resource (sometimes called an energy source) is a natural system (such as a waterfall) or store of energy (such as fuel) that we can use to make electricity.

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!

Can you work out the energy changes involved in everyday objects? Try this exercise.

Renewable and non-renewable energy resources

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. 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.

Only a small percentage of our total energy use comes from renewable energy resources. The rest is primarily made up of fossil and nuclear fuel sources which are non-renewable.

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.

The fossil fuels will be replaced you might argue! 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?)

Renewable	Primary Source	Energy Resource
		solar	Billions of photons of electromagnetic energy leave the Sun and hit our Earth every second.	The energy can be used directly by us in photo-voltaic cells and in solar heating panels.
		biomass	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 - this is eaten by animals to make animal material
		wind	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
		wave	The wind (see above) blowing on the water makes waves.	'Ducks' and OWCs can be used to convert the kinetic energy to electricity
		HEP	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
		geothermal	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
		tidal	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
Non-Renewable		nuclear	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
		coal	Fossil fuels - highly compressed, ancient once living matter (prehistoric biomass!) - a very concentrated form of chemical energy.	Made by photosynthesis and high pressure over a long time
		oil
		natural gas (methane)
LOJ - August 2003

Now revise the topic from flash cards I have written for:

Useful links:

http://www.dti.gov.uk/energy/ (The official government site on energy in the UK)

http://www.earthdog.com/renew.html

http://physicsweb.org/article/world/15/7/1/1

http://www.brainpop.com/science

http://www.darvill.clara.net/altenerg/index.htm (a site written by another UK physics teacher)