get wired to...planet science games
energise
what is power?
All that electricity buzzing through your computer right now didn’t just get magic-ed up to you. You got it from the National Grid, a network linking power stations to houses and businesses and schools, ready to energise our appliances with all that lovely heat, light and sound.
These power stations have to get it from somewhere too. And each of these sources of energy have their own environmental consequences.
Hydro energy involves ripping up land to make dams, nuclear fuel can be risky, and burning fossil fuels smogs up the world.
coal, oil, gas & nuclear power
mining
By far the most widely used resources for generating power today are the fossil fuels: coal, oil and gas. These were formed from decayed plants and animals that lived millions of years ago and are now mined and extracted from the Earth.
It’s worth remembering that the mined fossil fuels aren’t just burned as fuel, they’re also widely used in the petrochemical industry to make all sorts of things – from plastics to drugs.
The fuel used in nuclear power stations is also mined. Nuclear fuel is composed mostly of uranium; a metal created in supernova explosions long before the solar system was formed.
burning
Or rather ‘heating’ is another important concept. Fossil and nuclear fuels are used in a surprisingly similar way – to create heat. Coal, oil and gas are all simply burnt in air, whereas nuclear fuel is "fission" fuel. This means high-energy neutrons are fired at it, causing the nucleus of each atom to split, and thereby generating a huge amount of heat.
In both cases, the heat generated from the fuel is used to turn water into steam. The steam rises and is used to drive a turbine which generates the electricity. But for fossil fuels, the heating means burning – this causes lots of smoke and smog.
the environment
These Smog Jockeys in the real world aren’t just big energy firms. Anyone who wastes energy is behaving like a Smog Jockey. And most firms now use a mix of renewable and non-renewable resources.
We do need energy (to run a hospital and save lives, for a start), so its all a matter of deciding and choosing what we think is most important. Everything you decide to do has a consequence, and many of these are environmental.
difficult questions
Fossil fuel smog is more than just unpleasant when it stays in our air and gets in our eyes and lungs. Smog releases nitrogen oxides and sulphur dioxide into the atmosphere that can form acid rain. It also emits carbon dioxide which contributes to the greenhouse effect.
Nuclear energy is in some respects ‘cleaner’, as no polluting gases are produced. But instead, large quantities of radioactive waste are generated and the storage and disposal of this radioactive waster can be a dangerous issue.
These mined fuels will eventually run out. Should we be burning a resource that could be used to make a life-saving drug? Added to that, mining can seriously damage the landscape. Then again, so can hydroelectricity, so you can't find an easy answer there either.
The technology used to extract fossil fuels and use them to generate electricity is already available, making it one of the cheapest forms of electrical generation. And the technology involved in nuclear power is well established in making nuclear power a reasonably cheap form of electricity generation
wind power
Currently only about 1% of UK electricity is generated by wind power but this could be increased to nearly 10% within the next twenty years.
The UK is the windiest country in Europe and has relatively high average wind speeds, so it’s an appropriate place to use the wind in this way (shame the same can't be so easily said for solar energy!)
It may be surprising to realise that the energy we get from the wind originates in the Sun. There are lots of temperature differences on Earth – the Equator, the Poles, the ground, the sea and the air are all at different temperatures at different times. It’s the temperature differences that cause air to move, making all the wind. We can harness this wind and utilise it to make electricity.
Like many different types of electricity generation, the electricity produced by wind energy is created by a moving turbine. Wind flows over specially shaped blades making them spin. A series of gears means this motion is used to move a magnet within the turbine that generates electricity.
This last bit of the process (turning, movement into electricity) is key to most types of electricity production.
Wind power has many advantages over conventional fossil fuel or nuclear power. It doesn't produce any polluting gases or any waste products. The land can be used at the same time for crops or grazing animals and wind farm.
These are drawbacks to using wind power to generate electricity. Because the wind turbines need good wind speeds they have to be situated on open ground which makes an obvious eye-sore and have to be carefully situated so as not to spoil the beauty of the surrounding environment.
solar power
Solar power is the odd one out as far as electricity generation is concerned. The electricity is produced without turbines – instead the energy comes straight from the source. There are a variety of ways of using the sun’s energy, some much simpler than others and they don't all involve those funny looking cell things...
"Passive solar heating" requires clever building design. Large windows are built in south facing walls so that these rooms receive maximum light and heat, whereas north facing walls have small windows and are well insulated. By using this natural heat and light, far less electricity is required.
"Active solar heating" goes further and uses the Sun’s heat to warm tanks of hot water. This can be done by running the water through loads of black pipes on a roof or other sunny place. Black things absorb the heat from the sun; the water absorbs heat and then can be used in hot water systems in homes. This still requires some other power to pump the water round the homes, but this is a lot less than otherwise needed.
Solar power can also be used to generate electricity using photovoltaic cells. These are everywhere – look on a simple calculator. Basically, the sunlight causes electrons to move, creating an electric current.
The technology is still quite expensive and difficult to install, but solar power is a developing technology and it's getting more and more efficient. Maybe someday each home will be able to supply it’s own heating needs straight from the sun and use solar rays to generate it’s own store of electricity.
hydroelectric power
All moving water is moving because of energy, and hydroelectric power stations harness this energy to create electricity. Hydroelectric power currently supplies one fifth of the world’s electricity.
Like everything else on Earth, water ultimately gets its energy from the Sun. As we all know from endless science lessons on the water cycle, the Sun evaporates water from the oceans, rivers and lakes that then form clouds in the atmosphere. As the clouds rise over high land, they are no longer able to hold onto the water and it begins to rain.
Water originally in a low place (the ocean) in that way gets moved up to a high place (the mountain) giving it a load of potential energy. As the water then flows down hills through rivers, the potential energy is converted into kinetic (movement) energy. Hydroelectric power stations exploit this movement-energy and turn it into electricity through giant turbines.
Like solar and wind energy, hydroelectric power is ‘non-polluting’ but it does have its own environmental drawbacks. Water is usually stored in artificial lakes created by dams, this has often meant artificially flooding large areas of land, which in turn upsets existing ecosystems.
ready to play energise?
Against the clock and armed with your Eco-Raft your mission is to reduce pollution by converting the "Smog Jockeys" into users of alternative energy "Eco-Monkeys".
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