Showing posts with label PV tutorial. Show all posts
Showing posts with label PV tutorial. Show all posts

Thursday, July 1, 2010

The Advantage of Solar Energy over other Renewable Energy

There are several renewable energy sources such as Solar, Wind, Hydro, Biomass etc. All of the technologies has its own strength and weaknesses. In this blog, I want to explain about the advantages of Solar Energy.

http://library.thinkquest.org/07aug/01290/Solar_cell.png

Solar Energy has a main advantage over other technologies which is durable. It can be placed just outside your house and stand up to 30-40 years producing electricity for your needs which is longer than any other technology. Imagine yourself installing an array of PV cells at your rooftop. Just a one time installment and you have energy for 40 upcoming years of your life.

This technology can be durable because PV cells do not have any moving parts in it. This is really a striking point over any other techonology. In PV cells nothing moves or generates friction between parts such as in hydro or wind energy which uses generators and magnets to create electricity. The only thing that moves are the electrons generated by a wave of photons. This also means less costs and time for maintenance or breakdowns.

Another advantage of solar energy is that it does not produce any pollution to the nature. Wind energy could have the potential to create sound pollution because of the swinging blades. Hydro energy could have the potential to harm the nature or surrounding environment in the water. Solar energy does not have a negative effect to the nature.

These are the main advantages of solar energy over other renewable technologies. However, it doesn't mean that this technology is the perfect technology. There are several still some main disadvantages of solar energy which I will cover in my next blog.

Wednesday, June 30, 2010

How a basic photovoltaic cell works

Nowadays we see a lot of people placing solar cells on their roof. Solar cells are also known as photovoltaic cells. Photovoltaic comes from the photo which means "light" and voltaic which means "electricity". So basically, a photovoltaic cell uses light to create electricity. But how does it create electricity?

An average photovoltaic (PV) cell consists of 2 layers of silicon where most of the actions happens. It has antireflective coating to prevent the light that goes to the cell reflected away. The cell has metal conductor strips on it to conduct the electricity from the PV cell out to the load. It then gets back to metal backing of the cell to create a close loop.


Diagram of solar cell

A common material for silicon is the boron doped silicon and the phosphorus doped silicon. The phosphorus doped silicon contains more electron than the boron doped silicon.

Diagram of solar cell

This difference is necessary to create an electric field between the two layers. When these 2 types of silicon are joined together, the electron from the phosphorus doped silicon goes to the boron doped silicon side to create a stable environment. However, this happens only close to the junction of the joining point. Now the cell is ready for producing energy.


Diagram of solar cell

Now that the PV cell is ready, the sun comes play in generating energy. The sun sends a wave of photons (although it is also considered as particles of photons) to the earth. These photons have energy and are able to hit the electron in the PV cell. In reaction, the electrons spring out of their orbit and gets to the metal conductor strips.


Diagram of solar cell


Now that the electrons are captured and the potential difference is created, the only thing is to add a load (e.g. a lamp) to make a close circuit and the electrons are on the move to create its stability which in return powers up the load.

Diagram of solar cell

I hope that this blog can explain you about the basics of a photovoltaic cell in action. Feel free to comment or add knowledge/experience.

Note: Pictures are taken from PBS Nova site.