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Showing posts with label Solar Energy. Show all posts
Showing posts with label Solar Energy. Show all posts

Monday, July 2, 2012

Advantages of Solar Energy

When it comes to the future, solar energy is looking strong. People are now realizing that in the long term, solar energy provides a financially viable option. The upfronts costs might be high, but in the long term, everyone can save money by using solar energy. Here are some of the major advantages of solar energy.

Saving money is something that everyone is looking to achieve when it comes to solar energy. The great advantage of solar energy is that it utilizes a free energy resource; the sun. By utilizing the power of the sun, solar energy systems can create electricity. In fact, even if extra energy is produced, this can actually be sold to utility providers at a profit. Solar energy does not just save people money, but it can also make them money too.

A lot more people these days are focused on doing what is right for the environment. This includes things like producing energy. Power plants use a lot of non-renewable energy resources to provide our homes with power. Solar energy systems do not damage the environment in any way, so are good for the future of the planet.

One of the major advantages of solar energy is the lack of maintenance that is required in the long term. The systems do need slight maintenance every now and then, but in the long term, the costs are minimal. This means that once the initial investment has been made, there is little that a owner of a solar energy system really needs to do.

Read from : http://solarenergyfaq.net/

Wednesday, June 20, 2012

Solar Energy: Disadvantages of Solar Energy

In our discussion about advantages and disadvantages of solar energy, we have already discussed advantages of solar energy. Now lets take a look at disadvantages of solar energy.

However, this seemingly free source of energy is not free of cost in literal terms, let�s see how.

Too much exposure to sun rays can be harmful for the skin and may lead to skin problems. But the atmosphere acts as a sieve and removes a major part of the unwanted harmful rays of the sun. However, due to the global warming (caused due to release harmful gases into the atmosphere), the ozone layer has a hole in it now. Nature has provided us with all solutions to keep us safe and cozy, but it too demands care, or at least doesn�t want its own destruction. Utilizing its resources in the right manner is the only thing we can do. Over utilization has led us to a stage where we need to change the way we live and that comes at a huge monetary cost.

So, the choice is up to us. Whether we want to this big ball of fire to spoil our future for the present or refrain from harming the soil we have grown on, for a sustainable life.

Disadvantages of Solar Energy
1) Solar energy is mostly available in tropical and sub-tropical areas. The region with maximum Solar energy potential is lying between 50 degrees north and south of equator. As we move towards poles, proportion of solar energy received by earth goes on decreasing.
2) It is seasonal in nature and cannot be utilized during monsoon or when weather is cloudy.
3) The solar power technology is still at infant stage and is quite expensive.
4) Cost of installation of solar energy plant is very high.
5) During night it is not possible to produce Solar Energy.
6) Storage of this form of energy is difficult.
7) At present heavy machines are not possible to operate on this source.
8) Solar panels consume land, as power generation per unit square is low.
9) Silicon, used in production of SPV (Solar Photo Voltaic), is a pollutant.
10) Return of Investment(ROI) on solar energy takes around 3-5 years.

Keep Reading : http://www.ianswer4u.com/

Saturday, June 16, 2012

(2) What is Solar Energy?

Solar energy is energy that people can obtain for free. The sun produces energy every single day that is completely wasted, but now it can be used. By using a solar system, people can make use of the energy that the sun produces on a day to day basis. One of the most popular ways is to use photovoltaic cells in solar panels, that eventually are converted using a converter, into electricity.

Solar energy capturing has been done for a number of years. Nowadays there are extremely effective ways to do this, although the best is using solar panels. The solar panels absorb the rays from the sun, which creates energy. This energy can be easily converted into electricity to power the home. The great thing is, if there is any left, the owner can sell the electricity units to a utility supplier.

The main advantage of using solar energy rather than conventional energy resources is that they produce free energy. Instead of spending hundreds every month, people can now produce their own electricity for free. In fact, they can actually make money if they have extra energy to sell to utility suppliers.

There are a few barriers that stop a lot of people using solar energy. One of the major disadvantages and barriers of using solar energy is the fact that the upfront cost is extremely high. In many cases, it will cost thousands to produce and install a solar energy producing system, which means that a lot of people simply can not afford it.




Sumber : http://solarenergyfaq.net/

Friday, June 1, 2012

The Earth receives an incredible supply of solar energy

The Earth receives an incredible supply of solar energy. The sun, an average star, is a fusion reactor that has been burning over 4 billion years. It provides enough energy in one minute to supply the world's energy needs for one year. In one day, it provides more energy than our current population would consume in 27 years. In fact, "The amount of solar radiation striking the earth over a three-day period is equivalent to the energy stored in all fossil energy sources."

Solar energy is a free, inexhaustible resource, yet harnessing it is a relatively new idea. The ability to use solar power for heat was the first discovery. A Swiss scientist, Horace de Saussure, built the first thermal solar collector in 1767, which was later used to heat water and cook food. The first commercial patent for a solar water heater went to Clarence Kemp of the US in 1891. This system was bought by two California executives and installed in one-third of the homes in Pasadena by 1897.

Producing electricity from solar energy was the second discovery. In 1839 a French physicist named Edmund Becquerel realized that the sun's energy could produce a "photovoltaic effect" (photo = light, voltaic = electrical potential). In the 1880s, selenium photovoltaic (PV) cells were developed that could convert light into electricity with 1-2% efficiency ("the efficiency of a solar cell is the percentage of available sunlight converted by the photovoltaic cell into electricity"), but how the conversion happened was not understood. Photovoltaic power therefore "remained a curiosity for many years, since it was very inefficient at turning sunlight into electricity." It was not until Albert Einstein proposed an explanation for the "photoelectric effect" in the early 1900s, for which he won a Nobel Prize, that people began to understand the related photovoltaic effect.

"Solar technology advanced to roughly its present design in 1908 when William J. Bailey of the Carnegie Steel Company invented a collector with an insulated box and copper coils." By the mid-1950s Bell Telephone Labs had achieved 4% efficiency, and later 11% efficiency, with silicon PV cells. From then on, interest in solar power intensified. During the late 1950s and 1960s, the space program took an active role in the development of photovoltaics. "The cells were perfect sources of electric power for satellites because they were rugged, lightweight and could meet the low power requirements reliably." Unfortunately, the cells were not practical for use on earth due to the high cost of making them efficient and lightweight, so further research was necessary.

Solar energy may have had great potential, but it was left on the backburner whenever fossil fuels were more affordable and available. "Only in the last few decades when growing energy demands, increasing environmental problems and declining fossil fuel resources made us look to alternative energy options have we focused our attention on truly exploiting this tremendous resource." For instance, the US Department of Energy funded the installation and testing of over 3,000 PV systems during the 1973-1974 oil embargo. By the late 1970s, energy companies and government agencies had invested in the PV industry, and "a tremendous acceleration in module development took place." Solar energy improvements were again sought during the Gulf War in the 1990s.

Considering that "the first practical solar cells were made less than 30 years ago," we have come a long way.The profligation of solar professional companies designing unique and specific solar power systems for individual homes, means there is no longer an excuse not to consider solar power for your home. The biggest jumps in efficiency came "with the advent of the transistor and accompanying semiconductor technology." The production cost has fallen to nearly 1/300 of what it was during the space program of the mid-century and the purchase cost has gone from $200 per watt in the 1950s to a possible mere $1 per watt today. The efficiency has increased dramatically to 40.8% the US Department of Energy's National Renewable Energy Lab's new world record as of August 2008.

We still use solar power in the same two forms today, thermal and photovoltaic. The first concentrates sunlight, converts it into heat, and applies it to a steam generator or engine to be converted into electricity in order "to warm buildings, heat water, generate electricity, dry crops or destroy dangerous waste." Electricity is generated when the heated fluid drives turbines or other machinery. The second form of solar power produces electricity directly without moving parts. Today's photovoltaic system is composed of cells made of silicon, the second most abundant element in the earth's crust. "Power is produced when sunlight strikes the semiconductor material and creates an electric current." The smallest unit of the system is a cell. Cells wired together form a module, and modules wired together form a panel. A group of panels is called an array, and several arrays form an array field.

There are several advantages of photovoltaic solar power that make it "one of the most promising renewable energy sources in the world." It is non-polluting, has no moving parts that could break down, requires little maintenance and no supervision, and has a life of 20-30 years with low running costs. It is especially unique because no large-scale installation is required. Remote areas can easily produce their own supply of electricity by constructing as small or as large of a system as needed. Solar power generators are simply distributed to homes, schools, or businesses, where their assembly requires no extra development or land area and their function is safe and quiet. As communities grow, more solar energy capacity can be added, "thereby allowing power generation to keep in step with growing needs without having to overbuild generation capacity as is often the case with conventional large scale power systems." Compare those characteristics to those of coal, oil, gas, or nuclear power, and the choice is easy. Solar energy technologies offer a clean, renewable and domestic energy source.

Photovoltaic power even has advantages over wind power, hydropower, and solar thermal power. The latter three require turbines with moving parts that are noisy and require maintenance.

Solar energy is most sought today in developing countries, the fastest growing segment of the photovoltaics market. People go without electricity as the sun beats down on the land, making solar power the obvious energy choice. "Governments are finding its modular, decentralized character ideal for filling the electric needs of the thousands of remote villages in their countries." It is much more practical than the extension of expensive power lines into remote areas, where people do not have the money to pay for conventional electricity.

India is becoming one of the world's main producers of PV modules, with plans to power 100,000 villages and install solar-powered telephones in its 500,000 villages. By 2000, Mexico plans to have electrified 60,000 villages with solar power. Zaire 's Hospital Bulape serves 50,000 outpatients per year and is run completely on solar power, from air conditioning to x-ray equipment. And in Moroccan bazaars, carpets, tin ware, and solar panels lie side by side for sale. Probably the most outstanding example of a country's commitment to solar power is in Israel . In 1992, over half of all households (700,000) heated their water with solar energy systems. And there are 50,000 new installations every year.

Solar power is just as practical in populated areas connected to the local electrical power grid as it is in remote areas. "An average home has more than enough roof area to produce enough solar electricity to supply all of its power needs. With an inverter, which converts direct current (DC) power from the solar cells to alternating current (AC), which is what most home appliances run on, a solar home can look and operate very much like a home that is connected to a power line."

Household energy supply is but one use of solar power. There are actually four broad categories that can be identified for solar energy use: industrial, rural habitation, grid-connected, and consumer/indoor. Industrial uses represent the largest applications of solar power in the past 30 years. "Telecommunications, oil companies, and highway safety equipment all rely on solar power for dependable, constant power far from any power lines." Roadside call boxes and lighted highway signs rely on the sun's energy in order to provide reliable services without buried cable connections or diesel generators. Navigational systems such as marine buoys and other unmanned installations in harsh remote areas are also ideal applications for solar power because "the load demands are well known and the requirements for reliable power are the highest." Rural habitation includes "cabins, homes, villages, clinics, schools, farms, as well as individually powered lights and small appliances." Grid-connected systems pair solar power with an existing grid network in order to supply a commercial site with enough energy to meet a high demand, or to supplement a family's household supply. Consumer/indoor uses of PV cells include watches and calculators; PV modules power computers and radios.

The practicality and environmentally safe nature of solar power is influencing people worldwide, which is evident in equipment sales. According to Seimens Solar, production of PV cells and modules increased threefold from 40 MW in 1990 to about 120 MW in 1998. "Worldwide sales have been increasing at an average rate of about 15% every year during the last decade . We believe that there is a realistic possibility for the market to continue to grow at about a 15% rate into the next decade. At this rate, the world production capacity would be 1000 MW by 2010, and photovoltaics could be a $5 billion industry."

There are only two primary disadvantages to using solar power: amount of sunlight and cost of equipment. The amount of sunlight a location receives "varies greatly depending on geographical location, time of day, season and clouds. The southwestern United States is one of the world's best areas for sunlight . Globally, other areas receiving very high solar intensities include developing nations in Asia, Africa and Latin America ." See also sustainable house design

But a person living in Siberia would not benefit much from this renewable resource. And while "solar energy technologies have made huge technological and cost improvements, [they]are still more expensive than traditional energy sources." However solar equipment will eventually pay for itself in 2 to 5 years depending on h ow much sun a particular location receives. Then the user will have a virtually free energy source until the end of the equipment's working life, according to a paper called "Energy Payback Time of Crystalline Silicon Solar Modules." Future improvements are projected to decrease the payback time to 1 to 3 years.

The best way of lowering the cost of solar energy is to improve the cell's efficiency, according to Larry Kazmerski, Director of the DOE's National Center for Photovoltaics. "As the scientists and researchers at the NCPV push the envelope of solar-cell efficiency, we can begin to visualize the day when energy from the sun will be generating a significant portion of the country's electric power demand." Any improvements and subsequent cost cuts will also be vital to space applications.Also try finding the right Electric company in order to save money. Power companies can help you benefit with decisions such as this.

As the price of solar power lowers and that of conventional fuels rises, photovoltaics "is entering a new era of international growth." So much so, that solar power "will remain an excellent energy option, long after the momentary fossil fuel model fades into smoke."

Source : http://www.altenergy.org/

Thursday, January 5, 2012

Solar Energy

Solar Energy is the energy that is produced by the sun in the form of heat and light. It is one of the most renewable and readily available source of energy. The fact that it is available in plenty and free and does not belong to anybody makes it one of the most important of the non-conventional sources of energy. Solar energy has been used by people since ancient times by using simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire.

Mainly, Solar energy can be used to convert it into heat energy or it can be converted into electricity. Solar energy can be converted into electricity by means of solar thermal energy and photovoltaic. Through Solar Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. This form of energy can be used to power solar watches, calculators or traffic signals. They are often used in locations that are not connected to electricity grid. Solar heat energy can be used to heat water or space heating which means heating the space inside the building.

Solar energy can be broadly categorized as active or passive solar energy depending on how they are captured and utilized. In active solar energy special solar heating equipment is used to convert solar energy to heat energy whereas in passive solar energy the mechanical equipment is not present. Active solar include the use of mechanical equipment like photovoltaic cells, solar thermal collectors or pumps and fans to trap the solar energy. Passive solar technologies convert solar energy to heat energy without use of active mechanical systems. It is mainly the practice of using windows, walls, trees, building placement and other simple techniques to capture or deflect the sun for use. Passive solar heating is a great way to conserve energy and maximizing it's utilization. An example of passive solar heating is what happens to your car on a hot summer day.

Environmental Impact

Although Solar energy is considered to be one of the cleanest and renewable sources of energy among the available sources but is has some environmental impacts too. Solar energy uses photovoltaic cells to produce solar power. However, manufacturing the photovoltaic cells to produces that energy requires silicon and produce some waste products. Inappropriate handling of these materials may lead to hazardous exposure to humans and the environment. Installing solar power plants may require large piece of land, which may impact existing ecosystems. Solar energy does not pollute the air when converted to electricity by solar panels. It is found in abundance and does not help in global warming.

Future Of Solar Energy

Solar technology is now poised to play a larger role in the future, thanks to new developments that could result in lower costs and improved efficiency. In fact, the solar PV industry aims to provide half of all new U.S. electricity generation by 2025. More and more architects are recognizing the value of active and passive solar and learning how to effectively incorporate it into building designs. Solar hot water systems can compete economically with conventional systems in some areas. Perhaps the future is here now. Shell has predicted that 50% of the world's energy will come from renewable sources by 2040. In recent years manufacturing costs of photovoltaic cells has dropped by 3-5% per year while government subsidies have increased. While to some such facts about solar energy seem trivial, this makes solar energy an ever-more affordable energy source. In the next few years it is expected that millions of households in the world will be using solar energy as the trends in USA and Japan show. Aggressive financial incentives in Germany and Japan have made these countries global leaders in solar deployment for years.

Source : http://www.conserve-energy-future.com/SolarEnergy.php

Sunday, January 1, 2012

(1) What Is Solar Energy?

What is solar energy? Solar energy is the radiant energy produced by the Sun. It is both light and heat. It, along with secondary solar-powered resources such as wind and wave power, account for the majority of the renewable energy on Earth.

The Earth receives 174 petawatts(PW) of solar radiation at the upper atmosphere. 30% of that is reflected back to space and the rest is absorbed by clouds, oceans and land masses. Land surfaces, oceans, and atmosphere absorb solar radiation, which increases their temperature. Warm air containing evaporated water from the oceans rises, causing convection. When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds and causes rain. The latent heat of water condensation increases convection, producing wind. Energy absorbed by the oceans and land masses keeps the surface at an average temperature of 14�C. Green plants convert solar energy into chemical energy through photosynthesis. Our food supply is completely dependent on solar energy. After plants die, they decay in the Earth, so solar energy can be said to provide the biomass that has created the fossil fuels that we are dependent on.

Humans harness solar energy in many different ways: space heating and cooling, the production of potable water by distillation, disinfection, lighting, hot water, and cooking. The applications for solar energy are only limited by human ingenuity. Solar technologies are characterized as either passive or active depending on the way the energy is captured, converted, and distributed. Active solar techniques use photovoltaic panels and solar thermal collectors to harness the energy. Passive techniques include orienting a building to the Sun, selecting materials with thermal mass properties, and using materials with light dispersing properties.

Our current dependence on fossil fuels is slowly being replaced by alternative energies. Some are fuels that may eventually become useless, but solar energy will never be obsolete, controlled by foreign powers, or run out. Even when the Sun uses up its hydrogen, it will produce useable energy until it explodes. The challenge facing humans is to capture that energy instead of taking the easiest way out by using fossil fuels.

Source : http://www.universetoday.com/73693/what-is-solar-energy/

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