Solar Power and How it Works

With Calgary being the sunniest city in Canada (though you wouldn’t have guessed that the way the spring has been), we have a huge potential for both solar thermal and photovoltaic energy. One of our readers submitted the following article giving an overview into how solar power systems work.

(If you are a follower of UrbanCSA.org and would like to submit an article that you have written on a relevant topic, feel free to email us!)

Article by: Barbara Young

Drake Landing Solar Community in Okotoks: UrbanCSA hosts an annual tour of the solar community.

What is solar power ?

Solar power is radiant energy that is produced by the sun. Every 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 originates from within the sun itself. Like other stars, the sun is 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. 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 countless 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 speed of light.

Only a small portion of the power radiated from the sun into space strikes our planet, one part in two billion. Yet this volume of energy is enormous. Every day enough energy strikes america 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 power is also 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 would cause wood to catch fire. Over 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 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 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 right before The second world war. This growth lasted prior to the mid-1950s when low-cost propane became the primary fuel for heating American homes.

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

How we use solar energy today ?

Solar energy can be used in a variety of ways, of course. There’s two simple forms 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.

Listed below are the five most practical and popular ways that solar energy can be used:

1. Small portable solar photovoltaic systems. We have seen these used everywhere, from calculators to solar garden tools. 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 method 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 the sun’s rays and the heat is then transferred to water in a warm water tank. This method of collecting the sun’s energy is a lot 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 business power. In numerous parts of the world, solar photovoltaics is an economically feasible solution to supplement the power of your home. In Japan, photovoltaics are competitive with other kinds of power. In america alone, new incentive programs make this form of solar technology 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 usage of building integrated solar photovoltaics.

5. Large independent photovoltaic systems. If you have enough sun power at your site, you might be able to go off grid. You may also integrate or hybridize your solar power system with wind power or other kinds of alternative 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 electric power. The power created then flows into an inverter. The inverter transforms the energy into basic voltage and AC electric power.

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 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 power unfastens the electrons, permitting them to run freely. Solar 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 power ?

Solar Pro Arguments

– Heating our homes with oil or gas or using electricity from power plants running with oil and coal is a reason for climate change and climate disruption. Solar power, on the other hand, 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. Simply 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 help to eliminate the cost of the initial investment in solar technologies. The U.S. government, for instance, 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 first 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 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 con (solar space heating and the solar cooling systems) are expensive, and rather untested technologies: solar ac isn’t, till now, a really 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.

The author – Barbara Young writes on <a href=”http://www.12voltsolarpanels.net/rv-solar-panels-101-ultimate-guide-12-volt-battery-charging”>solar RV power</a> in her personal hobby weblog 12voltsolarpanels.net. Her efforts are dedicated to helping people save energy using solar powered energy to reduce CO2 emissions and energy dependency.

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2 comments

  1. Gene @ Diy Solar Panels · June 20, 2010

    The possibilities are huge for residential solar energy. With the rising cost of energy solar power will only become more attractive in the future.Solar power is important to the evolution of the society. It is important for countries, such as the United States, to move away from the dependency on foreign oil and to use energy resources that are readily available. No one can deny the sun isn’t a steady resource.

  2. Pingback: Solar Power Home » ‘10 Million Solar Roofs Bill’ Approved by Senate Energy Committee

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