For millions of years the sun has wrapped the world in it’s warmth and light, providing the necessities for life. Even now we are still finding many uses for the massive amount of energy the sun produces. Light travels to the earth in about eight seconds and is filled with little packets of energy called photons, which make utalizing this solar power possible.
There are three main ways to collect solar power. The first two are called passive system and active system. These use the sun’s energy to heat up an object which can be transferred to another object or an empty space. An active system’s power can even be turned into electricity. An even better way to get electricity from the sun is achieved by panels called photovoltaic cells. The sunlight is directly converted into electricity by the panels and can run almost anything, sunlight providing. These three different techniques show us that there can be many different ways to acquire power other than the conventional and hazardous methods we use today. Passive heating, thermal energy, and photovoltaics give the world many different ways to reap the benefits of solar power.
Passive heating is one of the most common and free ways to heat a house. It only requires common knowledge of the sun and how heat can be captured and stored. For example, a greenhouse works because the sun passing through the windows is trapped when it tries to escape. These types of principles are the basics to passive heating. Special window panes, wall, floors, roofs, and other materials are all called thermal mass. These also play a major role in passive heating because a certain material may hold heat better than another. Bricks and stones are often used because of their heat retention. They will warm up in the sun and can pass the heat to the inside, warming the room or house. Special windows can also be used. Double, triple pane windows with a special coating to stop heat from escaping lets in the light and insulates. It works like a one way mirror. On one side there is a mirror that reflects the image, while on the other a person can look through it. Passive heating is not only defined as using the right materials, but also the architecture of the building.
For instance, a house may have a roof over hang that blocks the sun from getting in the window in the summer, but during the winter it allows the sun to enter and warm the room (Hyde 37).
Another widely used strategy is placing the thermal mass facing the south (“Solar Energy.” 45).
Depending on the area this can be the most efficient direction that the sun comes from. The ideas of passive heating are not only ingenious, but also beneficial. With thermal mass there is never any mechanical parts to deal with unless some are added. There are also no wires! The heat is simply transferred by the material that absorbs it. This would have been beneficial in the past because of the lack of wires, electricity, or heating systems. Even now a house in the mountains could warm itself just by facing the right direction. This same principle can be taken with you where ever you go in the form or cardboard and ingenuity.
This is called a solar cooker. Light from the sun is reflected until it reaches the pot or item its supposed to heat. Solar cookers work amazingly well for being almost free and can cook a dinner in a couple of hours. They are mainly made up of tin foil and cardboard, cheap and easy, while others have been made from metal sheets to wooden boxes. The solar cooker was first invented in 1767 by a man called Horace de Sassure. He noticed how sunlight through a glass will heat up so he made a bow that had glass over it. When placed in the sun he notice the temperature rise and so he of course tried to insulate it and add more glass. The final product ended up reaching temperatures of 230 degrees F! this is still used today when people go camping or want a cheaper backyard bar-be-que
Another method that collects and uses solar energy is called an active system. The only major difference with and active system and a passive system is something that moves the energy around. For example water can absorb the heat quickly and can be run around a house to heat it. It can even be stored in big concrete tanks of stone and water called thermal mass. Running water through pipes that are exposed to the sun will heat up, but not nearly enough for the average home. To fix this problem black transparent panels are placed over the pipes to draw in more sunlight (“Solar Energy.” 46).
This also works for air, but without a pump or fan to move it around. The air is heated at the bottom of a system and rises up. As the warm air rises the cool air falls making a current. This is called a convection current. Another active system is a focusing collector.
Out in deserts and plains giant mirrors bounce the sunlight directly at towers or buildings that contain water. As the water is bombarded by many times the amount of energy from just sitting in the sun, it boils. Just like many other electrical systems, the heat generated creates steam which drives a generator (“Solar Energy” 46).
This system works very well because it only needs mirrors and a generator. A couple worldwide have already been built: “France began the operation of its first solar-generating plant there in January of 1977. One wall of the building is concave in shape and covered with reflecting mirrors that concentrate the rays of the sun on a boiler in front of them” (Hyde 40).
Active systems are also classified as using mirrors or other materials to focus the sun and use it. A brand new idea called solar sails has also shown itself. It fits in with active systems and uses mirrors and special materials to work. In the article “Space travel: And You Thought Windsurfing Was a Rush”, written by Michael Moyer for Popular Science, giant solar sails are the future in space travel. They work like a sail in the wind by using those little packets of energy called photons. As the sunlight hits the sail it bounces off harmlessly, but also pushes the sail just a little bit. When the area of the sail is increased, that one little photon is now millions, trillions, or even a googolplex of them hitting the mirrors. The idea certainly boggles the mind when light has no mass, but the energy from the sunlight works the same way. Spaceships could travel for centuries without using any conventional methods (Moyer 1).
Active systems are most beneficial over other methods of energy because they have no waste or pollution to soil the world with. Unlike nuclear power, which has radioactive waste, and oil, which pollutes, thermal plants only need water and sunlight to function.
Passive heating and active systems are both great ways to acquire a small part of the sun’s energy, but there is yet another way to harness this awesome power and turn it directly into electricity. It is known as photovoltaics and is one of the most useful ways of using the sun’s energy because it is directly converted into electricity without a middle median to lose energy at.
The solar cell works on a very small scale, all the way down to the atoms. The cell is made up of a positively charged layer and a negatively charged layer. When photons hit the negative charged particles electrons are knocked off. These lone electrons are forced to travel through a wire so that they may join with other atoms that are positively charged and stabilize them. In nature everything seeks a balance so it is natural for the electrons to move to fill an electron field (Aldous 1-6).
This creates a current that can be used to power almost anything. For example many companies have tried to successfully create a solar car that is inexpensive and still has that powerful feel to it. Usually the whole roof, front hood and back hood is cover with solar cells.
The interior of the car is basically one big battery. Houses, buildings, power plants, path lights, park water fountains, and numerous other objects can be controlled by this simple method. Since 1979 a radio station in Bryan, Ohio has been running fully off of photovoltaic power. Their system contains 33,600 cells to power newsrooms, production rooms, their signal and anything else they might need. Even thought they are still connected to the local power grid it is only used in emergencies. WNBO has really paved a way for future businesses to use solar power for themselves. The sun even works with business hours because at times that the most energy is required, the sun is at its most efficient point. Solar cells are very beneficial because they can turn direct sunlight into an electrical component. Without the hassle of special house designs and/or moving parts, they are the easiest to use, install, and manage.
A slight downfall is that they can be complicated to install because the electrical system in your house needs to be evaluated. Another benefit of photovoltaics is how personal it can be. The energy can be collected on your roof, stored in your basement and used by you and only you. With active systems more space could be required as it is not direct electricity, and it has to be converted first. You control your own energy, not some company that has thousands to millions of other homes to deal with. If the cells get enough sunlight a person could be taken totally off the electricity grid. In most states electric companies are required to buy extra energy off of your system, so selling your excess is always an option.. Not only do you not have to pay monthly, but you could gain money as well.
The three methods described are excellent ways to gain energy through the sun. They have many benefits that make conventional methods seem like pen and paper when compared to a typewriter. For instance they have no harmful emissions. Crude oil products are burned in order to create energy and can emit pollution, chemicals, and exhaust which is harmful to the earth. The chemicals in exhaust can eat at our ozone layer and pollution mixes with rain to make acid rain that poisons the environment. Passive systems requires nothing more than special designs and a knowledge of materials. Another asset of solar power is the fact that it is a renewable energy source. This means that unlike oil and coal, the sun will almost never run out.
We will always have sunlight that is chock full of energy. With gas prices climbing and oil reserves decreasing solar energy is the perfect replacement. The third benefit of solar power is the best of all, th fact that sunlight is free. There is no one that controls the distribution of sunlight or a soul that has the right too. All this energy is floating around you, warming your summers, and lighting the way to almost everywhere you go. Why not take advantage of it and heat your house, run your car, or cook at a camp-out without the dangers of leaving a fire on its own (“Solar Energy.” 111).
Using modern technology we have tapped into an abundant energy source and pulled out electricity to live off of. Sunlight is very practical for the necessities of human beings and has the possibility to replace other energy sources like crude oil and coal. Even though people can be taught the advantages of solar power, it takes action to put this information to good use. Solar power can be expensive because scientist have not found a more efficient way to trap the energy. Commercial photovoltaics cells can only trap about twenty percent of the sunlight that hits it. The other part of the light spectrum passes through it or bounces off. With numbers like these people wonder how its worth it to spend money when they can only get a fraction of the suns available energy.
Solar energy needs more support so that supply is below demand and it becomes cheaper to make. Other people also need to create more efficient ways to collect this energy. Even if half of the world knew about many of these benefits, solar power could have a brighter future. In some countries a plan to use more solar power and other renewable resources like wind and water power is already in place. Hopefully support will continue and countries may become fully dependent on renewable resources like solar power in the future.
Works Cited
Aldous, Scott. “How Solar Cells Work.” How Stuff Works HSW Media Network : A Convex Company. 11 May, 2004 http://science.howstuffworks.com/solar-cell.htm
“Horace de Saussure and his Hot Boxes of the 1700’s.” Solar Cookers International. 2001. 6 Feb, 2004 http://solarcooking.org/solarcooking-faq.htm
Hyde, Margaret. Energy: The New Look. New York, San Francisco: McGraw-Hill Book Co, 1981
Moyer, Michael. “Space Travel: And You Thought Windsurfing Was a Rush.” Popular Science 16 Aug, 2002 Website:www.popsci.com/popsci/aviation/artide/0,12543,337873,00.htm
“Solar Energy.” Macmillian Encyclopedia: Evironment 1997 ed. Pg 11-13