Renewable Energy

Renewable Energy

By Wassim Sayeg

All areas of life have impacted technology. It is the energy witch let us grow and which let us move. It is the heat and the light which we need to grow; there are many different kinds of energy.

When I ride my bicycle I need the energy my body produces. When my mom drives my dad’s car the car needs fuel to produce energy. When it is cold outside we need a lot of energy to heat our houses.

But where do we get this energy from?

There are about 6.464.750.000 human beings and each of us needs a lot of energy to survive and a lot of us waste a lot of energy and just a few of us are really responsible for it.

Some nations use coal, oil or gas to produce energy. These kinds of resources are called fossil fuels and they have been formed from the organic remains of prehistoric plants and animals (davill.clara.net). They are not renewable because fossil fuels took millions of years to form and don´t grow as fast as we use it. There will be a time when the resources of coal and oil are spent and the less resources we have, the more expensive these resources will get.

We have just been using oil and natural gas for less than 200 years and in about 100 years we will have wasted our planets ancient supply of these fossil fuels which are non-renewable because they exist in limited amounts.

But there are new resources which can be used for ever because they are constantly renewed and recycled in nature. These renewable recourses are called clean energy.

We can produce renewable energy out of the 4 elements: Fire (sun), water (ocean), earth (plants) and air (wind). They are the key to our clean and green future and with renewable energy we can make earth a better place.

1. Different kinds of renewable energy

1.1 Solar energy (fire- sun)

The sun is made out of hydrogen and helium this gases crash together and through this chemical reaction very high temperatures are reached since billions of years, the sun gets so hot that it glows. The energy travels in form of light through space like very fast waves on the ocean and needs just about 8 minutes to reach earth. The earth absorbs just one-billionth of the reached sun heat.

Many living organism on earth needs this sun heat to grow and to survive. Already 1000 a.c. Anasazu Indians in the southwestern Unites states used solar design to heat their houses in winter (Solar power page 29), today we use the sun energy to heat our homes or to power the electronics we need in our daily live. This kind of energy supported by sunlight is called solar energy.

Solar panels collect the sun light and turn it into heat or electricity, they can be placed everywhere and most people place them on the rooftops. A solar panel is build out of hundreds of solar cells and each of them is made out of silicon which is found in sand. When the silicon adsorbs sunlight a small electrical charge moves through the cells which are connected with batteries and the batteries store the electricity.

A little amount of cells can run a solar calculator and hundreds together can produce the energy need for a whole house. Since the 1950´s NASA use solar panels to power satellites in space because sunlight is always available.

Many deserts in America, North Africa and Europe are already homes of very large solar power stations which provide energy for many countries. They are perfect places because they get sunlight every day in the year. Curved mirrors concentrate the sunlight and are able to follow the sun.

1.2 Wind energy (air):

The wind energy is one of the oldest renewable energies. Already 200 B.C it was used in Persia (Iran) and in the 11th century people in the Middle East began to use windmills for food production, later merchants and crusaders brought this idea to Europe. Settlers took this technology to the New World in the late 19th century and began to use windmills to pump water for their farms and ranches, and in the 1920s Americans used small windmills to generate electricity in places without electric service. Wind is a very clean source of energy because windmills don´t need water for cooling and don´t destroy the natural environment.

Wind farms are usually built in flat, open areas where the wind blows very fast like big fields near to highways or to the coast and some fields are located out in the North Sea.

A windmill is about 30m tall and has usually three very shape blades. The blades are fixed on a tall tower and they rotate very fast when the wind blows. With their 3 blades they can reach speeds of over 320 km per hour. The energy of the movement of the blades gives power to a generator and the magnets inside the generator translate the energy of movement into electricity.

One windmill can produce the energy one house needs. Although wind energy is a clean energy some people don´t like it because they say that they look bad and make the natural environment ugly and many people don´t want to live next to windmills because the turbines make some noise. Sometimes the rotating blades kill birds that fly around.

1.3. Hydro energy (water- ocean):

Hydro energy is clean and renewable energy because it doesn’t cause global warming and doesn't release dangerous gases. Hydro energy is one of the is the oldest ways to produce energy. The first water wheels were invented about 2000 years ago in old Greek (Hydro comes from the Greek word for water) for making flower out of wheat and with the time it became a more a more effective way to produce clean energy and today it is the most important and widely-used renewable source of energy.

China is the largest producer of hydro energy, followed by Canada, Brazil, and the United States. Hydro energy uses the Earth's water cycle and converts the energy of water movement into electricity but it can't be used everywhere because it needs fast flowing water the whole year. The force of the water being trapped from the reservoir through the dam spins the blades of a giant turbine. The turbine is connected to a generator which creates electricity. After passing it to the generator the water flows back in the river. Hydro energy doesn’t soil the air but can affect natural water systems, wildlife and fish population in a negative way because it can kill or damage fish population and make the water quality worse.