What is solar energy ?
Solar energy is radiant energy which is produced by the sun. Each day the sun radiates, or sends out, an immense amount 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 mostly a big ball of gases––mostly hydrogen and helium atoms.
The hydrogen atoms in the sun’s core combine to form 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 requires many years for the energy in the sun’s core to make its way to the solar surface, after which 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 light.
Simply a small percentage of the power radiated from the sun into space strikes our planet, one part in two billion. Yet this quantity of energy is enormous. Everyday enough energy strikes the usa 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 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 energy is also absorbed by plants, the land, and the oceans. The rest could be employed to supply our energy needs.
Who invented solar energy ?
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 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 power in earnest. One important development was a remarkably efficient solar boiler introduced by Charles Greeley Abbott, a united states astrophysicist, in 1936.
The solar hot 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 prior to 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 technology to heat buildings and water and also to generate electricity.
How we use solar power today ?
Solar energy can be used in several different ways, of course. There are 2 simple types 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 below are the five most practical and popular ways that solar power can be used:
1. Small portable solar photovoltaic systems. We see these used everywhere, from calculators to solar garden tools. 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 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 sunshine and the heat is then transferred to water in a warm water tank. This process 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 business power. In many parts on the planet, solar photovoltaics is an economically feasible approach to supplement the power of your home. In Japan, photovoltaics are competitive with other forms 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 usage of building integrated solar photovoltaics.
5. Large independent photovoltaic systems. When you have enough sun power at your site, you may be able to go off grid. You may also integrate or hybridize your solar power system with wind power or other forms of renewable energy to stay 'off the grid.'
How do 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 power created then flows into an inverter. The inverter transforms the power into basic voltage and AC electric power.
Pv cells are prepared with particular materials called semiconductors such as 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 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 pros and cons of solar energy ?
Solar Pro Arguments
- Heating our homes with oil or gas or using electricity from power plants running with coal and oil is a reason for climate change and climate disruption. Solar energy, on the other hand, is clean and environmentally-friendly.
- Solar hot-water heaters require little maintenance, and their initial investment could be recovered within a relatively short time.
- Solar hot-water heaters can work in almost any 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 Water heaters or in Photovoltaic 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 ac (solar space heating and the solar cooling systems) are expensive, and rather untested technologies: solar air-con 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 the writer - Barbara Young writes on RV solar power kits in her personal hobby web log 12voltsolarpanels.net. Her work is dedicated to helping people save energy using solar energy to reduce CO2 emissions and energy dependency.