Tuesday, June 15, 2010
Let the Sun Shine On!
Today I received a delightful letter from one of my blog readers, named Barbara. She asked that I share this detailed article with you. She wrote it for you to read, learn and understand more about solar power!
Enjoy our guest blogger post, and thank you Barbara!
Here’s a simple way to learn the way solar panels work
What is solar power?
Solar power is radiant energy that is produced by the sun. Every single day the sun radiates, or sends out, an incredible amount 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 mostly 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 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.
Only 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. On a daily basis 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 our planet is reflected back to space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar power is absorbed by plants, the land, and the oceans. The rest could be used to supply our energy needs.
Who invented solar power?
Humans have harnessed solar power for centuries. 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'd cause wood to catch fire. Over a century ago in France, a scientist used heat from a solar collector to create steam to drive a steam engine. In the beginning of this century, scientists and engineers began researching ways to use solar technology in earnest. One important development was a remarkably efficient solar boiler introduced by Charles Greeley Abbott, an american astrophysicist, in 1936.
The solar 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 prior to World War II. This growth lasted before mid-1950s when low-cost natural gas became the primary fuel for heating American homes.
The public and world governments remained largely indifferent to the possibilities of solar technology until the oil shortages of the 1970s. Today, people use solar power to heat buildings and water and also to generate electricity.
How we use solar power today?
Solar power can be used in several different ways, of course. There are 2 very basic 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.
Listed here are the five most practical and popular methods solar energy is used:
1. Small portable solar photovoltaic systems. We have seen these used everywhere, from calculators to solar garden products. Portable units can be utilised for everything from RV appliances while single panel systems can be used traffic signs and remote monitoring stations.
2. Solar pool heating. Running water in direct circulation systems via a solar collector is an extremely 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 the sun's rays and the heat is then transferred to water in a warm water tank. Using this method of collecting the sun's energy is more practical now than ever. In areas as far north as Edmonton, Alberta, solar thermal to heat water is economically sound. It can pay for itself in 3 years or less.
4. Integrating solar photovoltaic energy into your home or office power. In lots of 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 the USA, new incentive programs make this form of solar power ever more viable in many states. A frequent and practical method 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. If you have enough sun power at your site, you may be able to go off grid. It's also possible to integrate or hybridize your solar power system with wind power or other types of sustainable energy to stay 'off the grid.'
How do 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 energy into basic voltage and AC electricity.
Pv cells are prepared with particular materials called semiconductors like silicon, which is presently the most generally used. When light hits the Photovoltaic cell, a certain 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 one or more 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.
Do you know the advantages and disadvantages of solar technology?
Solar Pro Arguments - Heating our homes with oil or natural gas or using electricity from power plants running with coal and oil is a reason for climatic change and climate disruption. Solar energy, on the contrary, is clean and environmentally-friendly. - Solar hot-water heaters require little maintenance, and their initial investment could be recovered within a relatively small amount of time.
- Solar hot-water heaters can work in almost any 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 aid in eliminating the price of the first investment in solar technologies. The U.S. government, as an 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 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 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 ac (solar space heating and the solar cooling systems) are expensive, and rather untested technologies: solar ac 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.
About the writer - Barbara Young writes on RV solar kits in her personal hobby website 12voltsolarpanels.net. Her work is related to helping people save energy using solar power to eliminate CO2 emissions and energy dependency.