Renewable energy is the answer

Claire G., Sara H. and Katelyn D.
Wodonga Senior Secondary College
Victoria, Australia

If you could change the world to make a better future, how would you do it? Two words; Renewable Energy! The burning of fossil fuels emits harmful gases and particles into our atmosphere which contributes to the enhanced greenhouse effect. By using renewable sources, we are able decrease the effect we are having on future generations, and one day even reverse damage already done.

Wind: Wind energy is, very simply, energy formed by the capture of power from the wind. Wind is created by areas of high air pressure, or heat, moving to areas of lower pressure, or cold and the uneven heating of the earth by the sun. Wind turbines have blades that are angled towards the direction of this pressure change and the wind produces movement of these blades, thus harnessing the energy, which is then converted to power. Currently, wind only makes up approx 1% of the worlds electricity usage, but equates to 19% of Denmark’s total production, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland.

Wind power is a reliable, clean, renewable and widely produced source of electricity which when harnessed to full potential, has the ability to power hundreds of thousands of homes. If wind is used in place of other major fuel sources whose impact on the environment is irreversible, then the future is cleaner, brighter, and longer for all of us.

Hydro: Hydro is a way to get energy from water, rivers to be more exact. Dams are built if possible, at the mouths of a gorge or valley, so as to force the water of a river to pile up behind the wall to form a lake. In the typical embankment dam a tunnel carries the water from behind the dam to a turbines in the power house. The flow of water into the tunnel is controlled by flood gates. The greater the drop between the turbine, the greater the force of water and the quantity of electricity generated.

Tidal: The movement of the tides can also be used to produce energy. The station produces power in much the same way as Hydro. A dam wall is built across the entrance of an inlet or bay, the moving water is passed through turbines. It can produce electricity as the tide comes in or out. Unfortunately there are very few sites that are suitable. Though another option is to use Off Shore turbines, theses look like an underwater wind farm. This has the advantage of being much cheaper to build, and does not have the environmental problems that a tidal barrage would bring.

Wave: Another water power in to use the waves. The amount of energy depends on the height and time between each wave. There are several ways of getting energy from waves, but one of the most effective works like a swimming pool wave machine in reverse. At a wave power station, the waves arriving cause the water in the chamber to rise and fall, which means that air is forced in and out of the hole in the top of the chamber. The turbine is placed on top of the chamber. We place a turbine in this hole, which is turned by the air rushing in and out. The turbine turns a generator.

All water energy is 80% efficient, and is getting more efficient all the time. 18% of all electricity is generated by hydropower, and 10% of Australia’s.

Solar: Solar energy is energy formed by heat and light from the sun. Solar power refers to the conversion of sunlight into electricity. Solar panels are also known as photovoltaic cells. These are made of two layers of silicon, which is a semi-conductor. The word photovoltaic is a made up of the Greek word for light 'photo', and ‘volt’, relating to electricity pioneer Alessandro Volta. By modifying the silicon used in solar cells the electrons can be unlocked. When light hits the solar cell it causes the electrons to move, creating an electric current. Solar cells can be used to provide power to homes and schools all over the world. There are a few factors that contribute to the efficiency of solar panels. They are; weather, and the amount of sunlight available, temperature and surprisingly the lower the temperature the more energy produced. This is because solar cells are electronic devices and generate electricity from light, not heat; therefore, they can operate more efficiently at lower temperatures. The cell configuration and technology also contributes.

Solar only supplies only about 0.05% of the world's electricity. While we can increase this immensely, it is improving constantly. The best thin-film solar cells at the moment are only 19.9% efficient.

Renewable energy is constantly being improved, and the governments are pushing to go more efficient but its us that need to push it more. We are the future; we are the ones that have to live in it, we are the only ones who can make it! The more we do know the less damage that is coerced. We can’t wait, or it will be too late. Renewable resources are the future. The quicker that planet comes round the better. So what are we waiting for? Together, we CAN change the future!

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