Solar power technologies and applications

Science - Solar Power (8th Grade)

SOLAR POWER

The current energy crisis is caused by our dependence on gasoline because there is not enough oil left in the world. That is because oil comes from the fossilized remains of ancient animals like dinosaurs buried deep in the earth. That is why it is called "fossil fuels" (Bobick, 1997). We have used so much of the fossil fuels that pretty soon there will be no more left for us to use anymore. To make sure that we have enough energy in the future, we have to find some other ways of making all the energy we need. One of the best new ways of making energy without oil is solar energy because the earth receives a constant supply of sunlight that is all free (Sachs, 2008).

If we could figure out how to use solar energy instead of gas powered energy, we would save a lot of money that we spend on oil. The other reasons that it is important to find different ways of getting energy are that gas power causes a lot of pollution and destroys the environment. Also, by using oil that we have to buy fro the Middle East, we are supporting some of the countries who support terrorism against the United States (Zuckerman, 2007).

Changing to Solar Power:

If we don't change to different forms of energy like solar power soon, we could run out of oil before we have a different way of making the energy we need. This problem has been known for a very long time but not much has been done about it yet. In 1930, we found 10 billion barrels of oil and we used only 1.5 billion. In 1964, we found 48 billion barrels of oil and we used 12 billion. Twenty years ago, we found 23 billion barrels of oil and we used 23 billion barrels. By the year 2005, we found only about 6 billion barrels of oil but we used 30 billion barrels (Zuckerman, 2007). It is obvious that oil will run out completely at this rate of discovery and use.

Solar energy works by capturing natural sunlight and then converting it in ways that make useful energy. There are two kinds of solar energy system. Passive solar energy systems work by catching the warmth from the sun and then using it. One example is new architectural designs that let enough sunshine into windows and skylights to warm houses without using oil or electric heat. Active solar energy systems work by storing energy from the sun and then letting us use some of that stored energy on demand (Bobick, 1997).

The problem is that not enough money is being spent on developing solar energy and other alternative sources of energy to oil. In the United States, only about three or four percent of our energy needs are provided by alternative energy sources. Experts believe that it may take so long to develop solar energy systems that alternative energy sources like solar energy will still make up less than five percent of our energy needs by the year 2030 (Lavelle, 2007).

Another big problem with changing over to solar energy is that it is very expensive. That is because to collect solar energy, you need very large collectors and a lot of land to build them on. The way solar energy systems work is that the sun's rays are collected by photovoltaic panels and they are very expensive to make (Lavelle, 2007).

One solution to that problem is using specially built mirrors instead of photovoltaic panels. However, even that solution still means that large solar energy systems need extremely large arrays of solar panels that are hundred of square feet. Right now, American companies like Pacific Gas & Electric (PG&E) are working on developing solar powered energy plants that use mirrors to concentrate sunlight and heat water. That water is used to power turbines that produce electricity the same way as old fashioned hydroelectric plants that use the energy of falling water in hydroelectric dams (Zuckerman, 2007).

Pacific Gas & Electric has started working on a big project of this kind and plans to increase the number of solar energy capture arrays by five times by using some of the deserts in the Southwest and Western states. They are also working on lowering the price of solar energy collectors. Solar collectors use silicon wafers that are too expensive to make and that is another reason that solar energy is still a lot more expensive than fossil fuel energy. Pacific Gas & Electric is working on a much thinner kind of silicon wafer that is put on glass (Lavelle, 2007).