Solar energy has existed for as long as the sun was born. Based on Wikipedia, our solar system was formed 4.6 billion years ago. It came from the gravitational collapse of a giant molecular cloud. This primal cloud was several light-years across and probably gave birth to several other stars as well. According to the meteorites study, the sun is formed from the shock waves of several supernovas’ explosions. The explosions caused many nebula regions to have overwhelmed density allowing gravitational forces to overcome internal gas pressure and collapsed forming the sun as we see today. Solar energy is the oldest form of energy known to mankind since we have been using it for thousands of years. Millenniums ago, human have been using solar energy to dry food and clothing. As early as the 7^th century BC, some of us discovered that when the sun ray is directed through a piece of glass, fire could start if the ray shines on something flammable. About 2000 years ago, the Greeks were the first to use solar housing. Their design is rather ingenious at that time allowing the run ray to pass through during the winter but not in the summer. Another intelligence idea ahead of it time was solar trapping. More than a thousand years ago, the Roman learned how to trap sunlight by building glass windows. They even created greenhouses so they can have fruit and vegetables the whole year.

Perhaps the greatest usage of solar energy ever discovered was the ability to turn solar energy directly into electricity. It is all begin with an experiment about solar energy named the photoelectric effect. This experiment is proposed by Einstein himself in 1905. In 1921, he won the Nobel Prize for this original proposal. The theory proposed that if sunlight is shine on the metal with a specific frequency corresponding to that metal, current is produced. Since current is the flow of electron, electricity is produced.

In 1954, the first photovoltaic technology is born when Daryl Chapin, Calvin Fuller, and Gerald Pearson developed the silicon photovoltaic cell at Bell Labs. The first solar cell invented is able to generate enough power from the sun to run everyday electrical equipments. At this time, the conversion of sunlight energy to electricity is still inefficient. As time passed, with the aid of new technology, photovoltaic cells are becoming more efficient along with the drop in manufacturing cost. Today, the technology has reached a point where photovoltaic cells are available for residential housing.

With the impressive potential of photovoltaic technology, many large companies like British Petroleum, Shell and the oil companies are already invested in this field. With the assist of Nanotech, development companies like Nanosys, Nanosolar and Konarka are reaching photovoltaic cells at a very low level. With this, they are hoping to increase the efficiency of energy collection to the point that the cost of solar energy is as low as the cost of fossil fuels. Perhaps with this amazing discovery, human have unlocked the key to a clean and prosperous future

Sources

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/07/11/BUG7IDL1AF1.DTL

http://en.wikipedia.org/wiki/Solar_system

http://www.solarenergy.org/resources/youngkids.html#2

http://www1.eere.energy.gov/solar/solar_time_1900.html

This is an interesting fact since Japan only takes up .3 percent of the world total landmass. The major reason behind it was simply matter of economic. In the last decade, electric price in Japan have been rising rapidly. Such increase in price was caused by many factors related to nuclear power plants.

For instance, according to vamasa.org, the incident in 1995 shut down the only fast breeder reactor in Japan. In 2003, all 17 of the nuclear plants managed by Tokyo Electric Power Company were also out of operation. These power plants were shut down because the government discovered that the company had been falsifying safety documentation. As a result, the vast majority of electricity generated in Japan is from burning coal & natural gas.

Due to limited supplies of coal & natural gas, Japan must import these resources from other countries. The result caused these energy goods to become increasingly more expensive as commodity prices continue an upward trend.

With their advance technology along with the government incentive, solar panels seem like the best choice to lower the energy cost.

Source:

http://yamasa.org

I know some of you just won’t take the simple answer above. For your sake and the sake of science, I like to dig deeper to find out how the whole process work.

Winds:

As the sun energy heats Earth’s surface, the surface heats the air above. The result of increase in energy will cause the air in the surrounding to move apart lowering the air density. This creates an area of low air pressure. Compare to other area which are not closely exposed to the sun radiation, air are much cooler. This cool air is closer together making it denser and heavier. As such, cool air will form an area of high pressure. To reach equilibrium, air will move from area of higher pressure to the area of lower pressure. Wind is the result of this process.

Ocean currents:
The Ocean represents a form of natural collection of solar energy. Upon absorbing solar energy, the water surface temperature increase. This increase in temperature causes water to expand creating a rise in altitude. The increase in altitude creates a slope causing the water to move. With the added effect of wind, water tends to move in a certain pattern called ocean currents. There you have it, a quick in-depth explanation of ocean currents.

In addition to winds and ocean currents, other weather patterns are created from solar energy. For instance, rain, lighting, tornado are the indirect results of solar energy. As long as there is a sun, weather patterns will continue to exist making the Earth an interesting place to live.

Sources

http://www.enotes.com/science-experiment/weather/what-causes-wind

http://www.marine.usf.edu/pjocean/packets/sp98/om_2.pdf

http://earth.usc.edu/~stott/Catalina/Oceans.html

Solar energy is the most abundant source of energy available to mankind. We will never run out of solar energy unless the sun dies. According to Wikipedia, there will another 7.8 billion years before the sun reach the next phase of evolution. This is the stage in which helium fusion will begin producing carbon and oxygen. By then, human race will either no longer exist or already came up with a solution to scope with the problem.

Beside it availability, it also have many useful characteristics that make it one of the most suitable form of energy. These characteristics are listed below:

Collect & Store:

Like most energy sources, solar energy can be collected and stored in almost any form of storage designed to hold energy. Energy storage like battery is very important if we want to involve solar energy in our modern way of life. We demand energy almost anytime and we expected to be available immediately. This is a problem since solar energy only available during daylight. For this reason, storing energy is a very crucial application. This application is usually integrated into solar photovoltaic system where energy collected and stored almost instantaneously.

In a typical photovoltaic system, sunlight shines upon the photovoltaic modules. Next, solar cells convert light energy into electrical energy producing direct current (DC). This current is stored directly into a battery. Since our home use Alternating Current (AC), an inverter is connected to the battery to convert from DC to AC. With this typical arrangement, solar energy can be effectively used to power our home.

Absorb:

According to the first law of thermodynamic, energy cannot be created or destroyed. Energy can only be transferred from one system or another. This concept spawns the property in which energy can be absorbed by a system or object. As solar energy shine upon the earth, any objects that are exposing to sunlight will have the potential to absorbed energy. For instance, if you leave your car outside on a sunny day it will become hotter as it slowly absorbing solar energy. With this basic property, we are indirectly obtained energy from the sun to power our everyday activities.

Transmit:

An interesting fact about nature is that there is an opposite of everything. If energy can be absorbed then it should be able to transmit. In fact, if no energy is transmitted then there is no energy to absorb. Therefore, the transmit property of energy is also very important.

Sources

http://en.wikipedia.org/wiki/Sun

http://en.wikipedia.org/wiki/Solar_energy#Energy_storage

http://en.wikipedia.org/wiki/First_law_of_thermodynamics

50% of the world’s energy comes from renewable sources by 2040 seems like a bold claim. According to Wikipedia, the total renewable energy in 2004 only constituted 7% of the total energy produced. This percentage came from hydroelectric. Perhaps the 7% from hydroelectric can be further expanded. And within the 36 long years, we can finally build a dam in every city. However, this is absolutely improbable.

Based on an article from ecotecture.com, there are numerous problems and limitations with power dams. Naturally, their constructions face tremendous obstacles. Their reservoirs destroy natural areas, farmlands and archeological treasures. Sometimes, such constructions would mean displacing masses of people from their home. Dams are also expensive to build and their reservoirs fill up with sands and others sediments rather quickly. For most dams, 50 to 75 years is how long it takes for sediments to fill up.

With the limitations of hydroelectric, why did Shell Oil made such a bold prediction that in 2040 “50% of the world’s energy will come from renewable source”? It is because solar energy is another form of renewable energy that may eventually solve the world energy problem of non-renewable fossil fuels depletion.

How can solar energy harvest through photovoltaic cells yield enough energy to power our daily need? This is not an easy question to answer since solar energy also faces many limitations. First of all, it is not available during night and it is weak on cloudy day. Secondly, solar modules are still very expensive even with much decrease in price over the last few years. Finally, electricity storage is still limited and usually dies out in several years.

Nevertheless, solar energy is very promising due to its impressive growth. According to solarbuzz.com, Solar Electric demand has grown consistently by 20-50 % each year over the pass 20 years. This is due to the increase in efficiency, manufacturing technology improvements and the economical reduction of cost when produce in large quantities. For this reason, large company such as Shell has a strong interested in the development of renewable energy. At this rate, solar energy could be the main source that powers our home in the next few decades.

Sources

http://www.alternate-energy-sources.com/facts-about-solar-energy.html

http://en.wikipedia.org/wiki/Future_energy_development

http://www.ecotecture.com/library_eco/energy/hydrogen1a.html

http://www.solarbuzz.com/StatsGrowth.htm

Photovoltaic is the technology in which light is converted into electrical energy. It is widely accepted today as a method for generating power by using solar cells packaged in photovoltaic modules. These modules are often connected in multiples as solar photovoltaic arrays which can be used to convert energy from the sun into electricity.

Based on Wikipedia, in the Sahara Desert with less cloud, it is possible to achieve 8.3 kWh/m²/day. The unpopulated area of the Sahara Desert is over 9 million km² (= 9×10¹² m²) which if covered with solar panel would provide:

- (8.3 kWh/m²/day) x (9×10¹² m²) x (3.6×10⁶ j/kWh) = 2.8682×10²⁰ j/day

The earth current energy consumption is 13.5 TW (13.5 x 10¹² W) = 13.5 x 10¹² j/s

- (13.5 x 10¹² j/s) x (60 s/m) x (60 m/h) x (24 h/day) = 1.1664×10¹⁸ j/day

Even considering bad weather conditions which reduce the strength of solar energy conversion by 4, the total energy converted from the Sahara Desert is still:

- (2.8682×10²⁰ j/day) / 4 = 7.1705×10¹⁹ j/day.

That is: 7.1705×10¹⁹ / 1.1664×10¹⁸ j/day = 61.47548 times larger than earth requirement.

Sources

http://en.wikipedia.org/wiki/Photovoltaics

http://en.wikipedia.org/wiki/Photovoltaic_array

Non-renewable energy is the condition used to describe sources of energy that are not easily renewed and could one day run out. These include coal, oil, natural gas and nuclear power. These energy sources beside nuclear power are gathered from the remains of fossil fuels.

Fossil fuels are compounds made of carbon and hydrogen. Millions of years ago these substances are the remains of plants and animals. As the plants and animals died, they were buried under sand and mud which stopped them from decaying. Over time, more sediment covered the remains. Along with heat and pressure, these remains are slowly being turned into coal, oil and natural gas.

The forming of fossil fuels began with plants and their energy gathering process from the sun called photosynthesis. That is why the sun is the main source accountable for these fossil fuels energy.

Sources

http://en.wikipedia.org/wiki/Fossil_fuel
http://www.lshc.co.uk/downloads/Nonrenewable.pdf

Many of us known Einstein as a genius who invented the equation E = mc². Others knew him as a physics pioneer who formulated the Theory of Relativity. However, what was least expected was that Albert Einstein actually won the Nobel Prize for his experiment with solar energy and photovoltaics. Einstein successfully demonstrated the photoelectric effect showing that light comes in a tiny discreet unit called photon.

Photoelectric effect occurred when a metallic surface is exposed to electromagnetic radiation above a certain frequency which is specific to the surface of the material. When the metallic surface receives light with the correct frequency, it will absorb the photons and produces current. With current comes electricity that we use to power all the electrical apparatus in our daily life. As such, this demonstrated the very basic concept of how we obtain solar energy.

Sources

http://en.wikipedia.org/wiki/Photoelectric_effect

There are many among us who have a deep concern about the welfare of the planet. If you are one, you will definitely find solar energy interesting. Solar energy is as natural it can get. It can be obtained abundantly from the sun and virtually every living organism on planet earth use it to continue its daily process. Even we human indirectly use solar energy to power our daily activities.

Our primary energy gathering process, to make it simple, begins with plants. Plants gather energy with the process called photosynthesis. It uses water, carbon dioxide, and sunlight to make glucoses.

The chemical equation for photosynthesis is:

- 6H₂O + 6CO₂ + (sunlight) → C₆H₁₂O₆ + 6CO₂

With the abundant of glucoses created by plants, we and other animals consume it to fulfill our daily energy need.

The chemical equation for glucose extraction is:

- C₆H₁₂O₆ + 6O₂ →  6CO₂ + 6H₂O + (energy)

Sources:

Photosynthesis: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html

Glucose Extraction http://www.tiem.utk.edu/bioed/webmodules/ATPEfficiency.htm

According to Wikipedia, the earth receives 174 petawatts (=1.74×10¹⁷ Watts) of incoming solar radiation at any given time. Only 89 petawatts is absorbed by land and oceans. The rest is radiated back into space. In 2004, the average total worldwide power consumption of our planet is 15 terawatts (=1.5 x 10¹³ Watts).

Doing basic math:

- (1.74×10¹⁷ Watts) – (.89×10¹⁷ Watts) = .85 x 10¹⁷ Watts x 2 = 1.7×10¹⁷ Watts
- (365 day/year) x (24 hr/day) = 8760 hr = 8.760 x 10⁴ hr/year
- (1.5x10¹³ Watts) x (8.760×10⁴) = 1.314×10¹⁷ Watts

- 1.7×10¹⁷ Watts ≥ 1.314×10¹⁷ Watts.

This shown that the total amount of solar energy reflected is vast. With a proper use of photo-voltaic technology, we can harvest this untapped energy supply to fulfill the world energy demand.

Sources:

http://en.wikipedia.org/wiki/Solar_energy

http://en.wikipedia.org/wiki/World_energy_resources_and_consumption