Saturday, June 19, 2010

The Importance of Solar Energy

Sunset at Rock in Rio Madrid

A reader wrote me about the Importance of Solar Power Energy in our world and I found the piece so helpful to all of us that I decided to share it, with her permission, here.

This really makes us understand the importance of this kind of energy in our days and the benefits of using it.

Take a moment to read the article and find out all about it.

Thank you Barbara Young for sharing it with all of us.

What exactly is solar energy ?

Solar energy is radiant energy that's produced by the sun. Every single day the sun radiates, or sends out, an immense quantity of energy. The sun radiates more energy in a single second than people have used since the beginning of time!

The energy of the Sun derives from within the sun itself. Like other stars, the sun is a big ball of gases––mostly hydrogen and helium atoms.

The hydrogen atoms in the sun’s core combine to create helium and generate energy in a process called nuclear fusion.

During nuclear fusion, the sun’s extremely high pressure and temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. However the helium atom contains less mass than the four hydrogen atoms that fused. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.

It requires millions of years for the energy in the sun’s core to make its way to the solar surface, and then somewhat over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of sunshine.

Simply a small portion of the energy radiated from the sun into space strikes the earth, one part in two billion. Yet this amount of energy is enormous. Every day enough energy strikes America to provide the nation’s energy needs for one and a half years!

Where does all this energy go?

About 15 percent of the sun’s energy which hits the earth is reflected back to space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar energy is also absorbed by plants, the land, and the oceans. The remaining could be used to supply our energy needs.

Who invented solar energy ?

Folks have harnessed solar power for hundreds of years. As early as the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire. Over 100 years ago in France, a scientist used heat from a solar collector to produce steam to drive a steam engine. At first of this century, scientists and engineers began researching ways to use solar energy in earnest. One important development was a remarkably efficient solar boiler introduced by Charles Greeley Abbott, an american astrophysicist, in 1936.

The solar hot water heater became popular at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing right before World War II. This growth lasted prior to the mid-1950s when low-cost natural gas became the primary fuel for heating American homes.

People and world governments remained largely indifferent to the possibilities of solar technology prior to the oil shortages of the1970s. Today, people use solar power to heat buildings and water and also to generate electricity.

How we use solar energy today ?

Solar power is used in a number of different ways, of course. There's two standard forms of solar energy:

* Solar thermal energy collects the sun's warmth through 1 of 2 means: in water or in an anti-freeze (glycol) mixture.

* Solar photovoltaic energy converts the sun's radiation to usable electricity.

Here are the five most practical and popular methods solar energy is used:

1. Small portable solar photovoltaic systems. We see these used everywhere, from calculators to solar garden tools. Portable units may be used for everything from RV appliances while single panel systems are used for traffic signs and remote monitoring stations.

2. Solar pool heating. Running water in direct circulation systems through a solar collector is an extremely practical way to heat water for your pool or hot spa.

3. Thermal glycol energy to heat water. In this method (indirect circulation), glycol is heated by natural sunlight and the heat is then transferred to water in a hot water tank. Using this method of collecting the sun's energy is much more practical now than ever before. In areas as far north as Edmonton, Alberta, solar thermal to heat water is economically sound. It can pay for itself in three years or less.

4. Integrating solar photovoltaic energy into your home or office power. In lots of parts of the world, solar photovoltaics is an economically feasible method to supplement the power of your property. In Japan, photovoltaics are competitive with other types of power. In the US, new incentive programs make this form of solar energy ever more viable in many states. An increasingly popular and practical way of integrating solar energy into the power of your home or business is through the usage of building integrated solar photovoltaics.

5. Large independent photovoltaic systems. For those who have enough sun power at your site, you might be able to go off grid. It's also possible to integrate or hybridize your solar power system with wind power or other kinds of sustainable energy to stay 'off the grid.'

How can Photovoltaic panels work ?

Silicon is mounted beneath non-reflective glass to produce photovoltaic panels. These panels collect photons from the sun, converting them into DC electric power. The power created then flows into an inverter. The inverter transforms the power into basic voltage and AC electricity.

Pv cells are prepared with particular materials called semiconductors for example silicon, which is presently the most generally used. When light hits the Photovoltaic cell, a specific share of it is absorbed inside the semiconductor material. This means that the energy of the absorbed light is given to the semiconductor.

The energy unfastens the electrons, permitting them to run freely. Solar power cells also have more than one electric fields that act to compel electrons unfastened by light absorption to flow in a specific direction. This flow of electrons is a current, and by introducing metal links on the top and bottom of the -Photovoltaic cell, the current can be drawn to use it externally.

What are the advantages and disadvantages of solar power ?

Solar Pro Arguments

- Heating our homes with oil or propane or using electricity from power plants running with coal and oil is a cause of climatic change and climate disruption. Solar power, on the contrary, is clean and environmentally-friendly.

- Solar hot-water heaters require little maintenance, and their initial investment can be recovered within a relatively limited time.

- Solar hot-water heaters can work in nearly every climate, even just in very cold ones. You just need to choose the right system for your climate: drainback, thermosyphon, batch-ICS, etc.

- Maintenance costs of solar powered systems are minimal and also the warranties large.

- Financial incentives (USA, Canada, European states…) can reduce the price of the initial investment in solar technologies. The U.S. government, for example, offers tax credits for solar systems certified by by the SRCC (Solar Rating and Certification Corporation), which amount to 30 percent of the investment (2009-2016 period).

Solar Cons Arguments

- The first investment in Solar Water heaters or in Solar PV Electric Systems is higher than that required by conventional electric and gas heaters systems.

- The payback period of solar PV-electric systems is high, as well as those of solar space heating or solar cooling (only the solar hot water heating payback is short or relatively short).

- Solar water heating do not support a direct in conjunction with radiators (including baseboard ones).

- Some air cooling (solar space heating and the solar cooling systems) are very pricey, and rather untested technologies: solar air-con isn't, till now, a truly economical option.

- The efficiency of solar powered systems is rather dependent on sunlight resources. It's in colder climates, where heating or electricity needs are higher, that the efficiency is smaller.

The author - Barbara Young writes on motorhome solar panels in her personal hobby weblog 12voltsolarpanels.net. Her efforts are dedicated to helping people save energy using solar powered energy to lower CO2 emissions and energy dependency.
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