Just in time for the hot and sunny summer, Barbara Young, owner of 12 Volt Solar Panels, has guest authored this great post on Solar Power energy and Solar Panels.
Now more than ever we should take action on reducing our dependence on oil - foreign or otherwise - and seek environmentally safe alternatives wherever possible. Solar energy is one way and the more we know about it, the better, as far as I am concerned. There are many ways to go about this such as Sunforce 39126 246-Watt High-Efficiency Polycrystalline Solar Power Kit or reading up with Solar Power Your Home For Dummies (For Dummies (Home & Garden))
Barbara Young give a great overview of how Solar power works and how Solar Panels work. She also writes about the pros and cons of solar power in this great overview: Here’s a simple way to learn how solar panels work.
What is solar power ?
Solar power 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 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 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 takes millions of years for the energy in the sun’s core to make its way to the solar surface, after which slightly 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.
Only a small percentage of the power 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 the United States 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 planet earth is reflected back into 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 technology ?
Humans have harnessed solar technology 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. More than 100 years 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 invented by Charles Greeley Abbott, an American astrophysicist, in 1936. The solar water heater came into common use at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing just before WW II. This growth lasted prior to the mid-1950s when low-cost natural gas took over as primary fuel for heating American homes.
People and world governments remained largely indifferent to the possibilities of solar energy until the oil shortages of the 1970s. Today, people use solar power to heat buildings and water and to generate electricity.
How do we use solar power today ?
There are 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 techniques solar energy is employed:
1. Small portable solar photovoltaic systems. We see these used everywhere, from calculators to solar garden tools. Portable units can be utilized 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 method to heat water for your pool or 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. 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 most parts of the world, 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 the USA, new incentive programs make this form of solar technology 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 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. It's also possible to integrate or hybridize your solar power system with wind power or other kinds of renewable power 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 electrical energy. The energy created then flows into an inverter. The inverter transforms the energy 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 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 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.
The benefits and drawbacks of solar energy
Solar Pro Arguments
- Heating our homes with oil or natural gas or using electricity from power plants running with coal and oil is a cause of 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 could be recovered in just a relatively short time.
- Solar hot-water heaters can work in nearly every climate, even just in very cold ones. You just need to choose the best 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 help to eliminate the cost of the first 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 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 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 con (solar space heating and the solar cooling systems) are costly, and rather untested technologies: solar air conditioning 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 guest blogger Barbara Young: Barbara writes on Rv Solar Panels in her personal hobby site 12voltsolarpanels.net. Her efforts are related to helping people save energy using solar powered energy to eliminate CO2 emissions and energy dependency.