What is alternative energy and what are some examples?
Monday, May 17th, 2010 at
8:27 am
I need a few examples of alternative energy and what it is.
Tagged with: alternative energy
Filed under: Clean Energy
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Alternative energy is a term that refers to methods of generating energy that are not the usual method (i.e. fossil fuels). There are many forms of alternative energy, but, as energy is conserved, you have to ask yourself where the energy comes from (and the answer is always "the sun"). You should always be careful when you look at energy forms, because some of them just won’t work – like the idea of putting water in your gas tank that another user has suggested (thermodynamics shows that these ideas won’t work).
The sun undergoes nuclear reactions which result in the release of photons (beams of light that have energy associated with them). Alternative energy forms just capture the energy from the sun in different ways (actually, fossil fuels also got their energy from the sun a long time ago).
Here are a few alternative energy sources and how they relate to the sun:
Bio-fuels: We can grow plants (such as algae, corn, sugar cane) which collect the photons from the sun and use the energy in the photons to create sugars. We can harvest those sugars and and turn them into liquid fuels such as ethanol.
Solar Energy: This technology directly harnesses the energy of the sun by absorbing photons through photovoltaic solar cells and which create an electrical current when they absorb a photon. Additionally, you can use the energy of the sun to thermally heat an object, which is referred to as solar-thermal energy.
Wind Energy: When the photons from the sun hit the air in the atmosphere, that energy can cause the generation of wind. We can harvest the wind energy by using turbines which spin when the wind hits them. The spinning motion is used to turn a generator which produces electricity.
Hydro-electric: When the sun hits water, it can cause the water to turn into a gas and later that gas can result in rain. If the rain occurs at a high enough elevation and gets held behind a dam, the water now possesses a high potential energy due to the energy from the sun. That energy can be turned into electrical energy by converting the potential energy of the water into kinetic energy which is then used to turn a turbine in a hydroelectric dam.