I've not updated this for so long, but Barbara has kindly written an article on solar energy (especially in the light of the messy oil spills here in Singapore and in the Gulf of Mexico) which I'm going to stick below, so here goes!
Here’s a simple method to learn the way solar panels work
What is solar energy ?
Solar energy is radiant energy that's produced by the sun. Each day the sun radiates, or sends out, a huge volume 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 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. However 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 many 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 light.
Only a small percentage of the energy radiated by the sun into space strikes our planet, one part in two billion. Yet this amount of energy is enormous. Every single day enough energy strikes the united states to provide the nation’s energy needs for one and a half years!
Where does all of this energy go?
About 15 percent of the sun’s energy which hits the planet earth is reflected back into space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar power also is absorbed by plants, the land, and the oceans. The rest could be employed to supply our energy needs.
Who invented solar power ?
People have harnessed solar power for hundreds of years. Since 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 energy 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 gained popularity 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 gas became the primary fuel for heating American homes.
People and world governments remained largely indifferent to the possibilities of solar technology until the oil shortages of the1970s. Today, people use solar technology to heat buildings and water and to generate electricity.
How we use solar power today ?
Solar power is employed in several different ways, of course. There's two simple forms of solar power:
* 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 techniques solar energy is employed:
1. Small portable solar photovoltaic systems. We have seen these used everywhere, from calculators to solar garden products. Portable units can be used 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 solution to heat water for your pool or hot tub.
3. Thermal glycol energy to heat water. In this method (indirect circulation), glycol is heated by sunshine and the heat is then transferred to water in a warm water tank. This method of collecting the sun's energy is more practical now than in the past. 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 office power. In most parts on the planet, solar photovoltaics is an economically feasible method to supplement the power of your property. In Japan, photovoltaics are competitive with other kinds of power. In america alone, new incentive programs make this form of solar power ever more viable in many states. An increasingly popular 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. For those who 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 energy system with wind power or other forms of sustainable energy to stay 'off the grid.'
How can Photovoltaic panels work ?
Silicon is mounted beneath non-reflective glass to create photovoltaic panels. These panels collect photons from the sun, converting them into DC electrical energy. The energy created then flows into an inverter. The inverter transforms the power into basic voltage and AC electrical power.
Solar 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 particular 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.
Do you know the advantages and disadvantages of solar energy ?
Solar Pro Arguments
- Heating our homes with oil or natural gas or using electricity from power plants running with fossil fuels is a reason for global warming 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 in just a relatively small amount of time.
- Solar hot-water heaters can work in almost any climate, even 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 cost 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 Hot water heaters or in Solar PV Electric Systems is greater 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 very pricey, and rather untested technologies: solar air conditioning isn't, till now, a really economical option.
- The efficiency of solar powered systems is rather influenced by sunlight resources. It's in colder climates, where heating or electricity needs are higher, that the efficiency is smaller.
About me - Barbara Young writes on solar power kits in her personal hobby website 12voltsolarpanels.net. Her work is devoted to helping people save energy using solar powered energy to eliminate CO2 emissions and energy dependency.
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