guest article by Barbara Young

Here’s a simple option to learn how solar panels work

What is solar energy ?

Solar power is radiant energy which is produced by the sun. Daily the sun radiates, or sends out, an incredible quantity of energy. The sun radiates more energy in a second than people have used since the beginning of time!

The energy of the Sun originates from within the sun itself. Like other stars, the sun is really 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. But the helium atom contains less mass compared to four hydrogen atoms that fused. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.

It takes an incredible number of years for the energy in the sun’s core to make its way to the solar surface, and then just a little 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 velocity 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 quantity of energy is enormous. Each day enough energy strikes the usa to supply 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 that hits the earth is reflected back to space. Another 30 percent is used to evaporate water, which, lifted in to the atmosphere, produces rainfall. Solar energy is absorbed by plants, the land, and the oceans. The rest could be employed to supply our energy needs.

Who invented solar technology ?

People have harnessed solar energy for years and years. Since 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. More than a century ago in France, a scientist used heat from a solar collector to make steam to drive a steam engine. At first of this century, scientists and engineers began researching ways to use solar technology in earnest. One important development was obviously a remarkably efficient solar boiler invented by Charles Greeley Abbott, a united states astrophysicist, in 1936.

The solar water heater gained popularity at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing just before World War II. This growth lasted until the mid-1950s when low-cost propane took over as primary fuel for heating American homes.

The public and world governments remained largely indifferent to the possibilities of solar power before oil shortages of the1970s. Today, people use solar energy to heat buildings and water and to generate electricity.

How we use solar power today ?

Solar power is used in several different ways, of course. There's two very basic types of solar energy:

* Solar thermal energy collects the sun's warmth through one of two 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 ways that solar energy is used:

1. Small portable solar photovoltaic systems. We have seen these used everywhere, from calculators to solar garden products. 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 via a solar collector is a very practical method 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 36 months or less.

4. Integrating solar photovoltaic energy into your home or business power. In many parts on the planet, solar photovoltaics is an economically feasible solution to supplement the power of your home. In Japan, photovoltaics are competitive with other types of power. In america, new incentive programs make this form of solar energy ever more viable in many states. A frequent and practical way of integrating solar energy into the power of your home or business is through the use of building integrated solar photovoltaics.

5. Large independent photovoltaic systems. For those who have enough sun power at your site, you could possibly go off grid. It's also possible to integrate or hybridize your solar energy system with wind power or other types of renewable power 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 electrical power. The power created then flows into an inverter. The inverter transforms the power into basic voltage and AC electricity.

Solar cells are prepared with particular materials called semiconductors like 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. Pv 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 natural gas or using electricity from power plants running with fossil fuels is a reason behind 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 may be recovered in just a relatively small amount of time.

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

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

- Financial incentives (USA, Canada, European states…) can aid in eliminating 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 initial investment in Solar Hot water heaters or in Photovoltaic 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 domestic hot water heating payback is short or relatively short).

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

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

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

About the Author - Barbara Young writes on motorhome solar power in her personal hobby web log 12voltsolarpanels.net. Her efforts are related to helping people save energy using solar energy to eliminate CO2 emissions and energy dependency.