Everything you need to know about solar energy

By TBS Activist Contributor Barbara Young.

Image via. Barbara writes about solar power on her personal web site 12voltsolarpanels.net. Her work is centered on helping people save energy using solar power to lower CO2 emissions and energy dependency.

What is solar energy?

Solar energy is radiant energy which is produced by the sun. Daily the sun radiates, or sends out, an incredible quantity 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 comes 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 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 requires an incredible number of years for the energy in the sun’s core to make its way to the solar surface, and slightly over eight minutes to travel the 149.6 million kms to earth. The solar energy travels to the earth at a speed of 300,000 miles per second, the velocity of sunshine.

Only a small percentage of the power radiated by 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 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 the planet earth is reflected back to space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar energy is absorbed by plants, the land, and the oceans. The remaining could be employed to supply our energy needs.

Who invented solar energy ?

People have harnessed solar energy for hundreds of years. 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. Over 100 years ago in France, a scientist used heat from a solar collector to produce 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 obviously a remarkably efficient solar boiler invented by Charles Greeley Abbott, a united states astrophysicist, in 1936.

The solar hot 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 The second world war. This growth lasted until the mid-1950s when low-cost natural 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 power to heat buildings and water and to generate electricity.

How do we use solar power today ?

Solar energy is used in several different ways, of course. There are two simple kinds 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 techniques solar energy can be used:

1. Small portable solar photovoltaic systems. We have seen these used everywhere, from calculators to solar garden products. Portable units can be utilized 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 tub.
   
   
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. This technique of collecting the sun's energy is more practical now than in the past. It can pay for itself in 36 months or less.
   
   
4. Integrating solar photovoltaic energy into your home or office power. In numerous parts on the planet, solar photovoltaics is an economically feasible method to supplement the power of your own home. In Japan, photovoltaics are competitive with other types of power. 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. 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 renewable power to stay 'off the grid.'

How can 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 power. The energy created then flows into an inverter. The inverter transforms the power into basic voltage and AC electrical power.

Photovoltaic 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.

What are 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 fossil fuels is a reason for climate 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 can be recovered within a relatively short time.
  
  
• Solar hot-water heaters can work in nearly every climate, even in very cold ones. You just have 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 reduce 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 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 expensive, 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.