Posts Tagged ‘Alexandre-Edmond Becquerel’

3 April

What Is Solar Cell (7)

Share

If you are in favor of renewable/CLEAN energy, please sign the petition page showing support for FIT/CLEAN Program at http://sunisthefuture.net/?page_id=1065 Thank you.

By now, dear readers/friends, you are probably wondering how much of the world’s energy usage is based on solar energy. Despite the fact that it is by far the most “clean, safe, abundant, and least likely to contribute to war among nations” form of energy, it is only taking up about 0.5%

World Energy Usage Chart (Note:Solar heat of 0.5%, Wikimedia Commons)

of the world’s energy usage. The reason is cost!  That is why scientists and engineers throughout planet earth are making their greatest effort in figuring out /experimenting with material and ways of applying technology to reduce the cost of solar energy/technology.  Thin film technology reduces the amount of material required to create a solar cell, but it also reduces the energy conversion efficiency.  Nevertheless, thin film silicon cells have become popular due to cost, flexibility, lighter weight, and ease of integration, compared to wafer silicon cells.  In this next and final clip on the series of “What Is Solar Cell”,  you will see CIGS (copper indium gallium selenide. some also call it CIGSS or (di)selenide, but most literatures refer to it as CIGS), a direct-bandgap material, with the highest efficiency (~20%) among thin film materials.

You will find this clip at http://www.youtube.com/watch?v=SMnx5tFrDDc&feature=related or simply click below:

 

It is encouraging that solar industry had been growing exponentially in recent years and its cost had been driven down tremendously.  In addition to decreasing the cost, increasing the efficiency of the material, and increasing its applications ( building integrated photovoltaics such as roof, window glass, or paint, using thin film solar material will drive down the cost of solar electricity further and eventually be able to get 20% of the energy from solar (forecasted by some scientists and engineers)) , there had been great amount of discussions in various types of incentive programs that may be implemented in the effort of driving down its cost and increasing its economic feasibility.  In the final analysis, in order to increase the percentage of global energy use from solar energy, it is up to all of us earthlings to make every effort in bringing down the cost of solar technology, whether through scientific technological research and development or through incentive programs.  I will reserve the topic on various incentive programs in future posts. Until then, I bid you a clear and sunny day tomorrow~

Posted by sunisthefuture-Susan Sun Nunamaker,sunisthefuture@gmail.com
Homepage: http://sunisthefuture.net http://sunisthefuture.com http://sunisthefuture.org

Share
1 April

What Is Solar Cell (1)?

Share

If you are in favor of renewable/CLEAN energy, please sign the petition page showing support for FIT/CLEAN Program at http://sunisthefuture.net/?page_id=1065 Thank you.

Due to popular demands/requests, I am going to present a series of discussions on solar cell .  A solar cell is also known as photovoltaic cell or photoelectric cell that converts the sunlight/light energy directly into electricity by the photovoltaic effect (the creation of a voltage or a corresponding electric current in a material upon exposure to light). http://www.youtube.com/watch?v=fixI-xZ3U_M   click below:

 

In the photovoltaic effect, the generated electrons are transferred between different bands (i.e. from the valence to conduction bands) within the material, resulting in the buildup of a voltage between two electrodes;this  effect was first observed by Alexandre-Edmond Becquerel in 1839.

Photovoltaic cells are simply cells whose light source is not necessarily of sunlight whereas solar cells are cells whose light source is that of sunlight. When  solar cells are electrically connected and encapsulated as a module to make solar modules or solar panels, solar power/energy is generated from these solar modules/panels.  Solar or photovoltaic modules usually have a sheet of glass on the front (sun up) side, allowing light to pass while protecting the semiconductor wafers from abrasion and impact due to rain, hail, debris, etc. Most of the solar cells of the solar panels on the market now a days are made of either monocrystalline silicon or polycrystalline silicon.  Monocrystalline solar cell (darker/black) is more expensive and have higher efficiency than that of polycrystalline silicon.

A solar cell made from a monocrystalline silicon wafer (Source:Wikimedia Commons)

Polycrystalline photovoltaic cells laminated to backing material in a module (Source: Wikimedia Commons)

Modules are then interconnected, in series or parallel or both, to create an array with the desired peak DC voltage and current.  Then the solar generated energy/electricity is often fed into the electricity grid using inverter (a device that converts direct current to alternating current);in stand-alone systems, batteries are used to store the energy for future use.  Solar panels may be used to power or                                                                                  charge portable devices.  For those of you who are thinking of projects or demonstrations for your students or children, please stay tuned in for my next blog.

~Be well and have a sunny day~

Posted by sunisthefuture-Susan Sun Nunamaker, sunisthefuture@gmail.com
Homepage: http://sunisthefuture.net http://sunisthefuture.com http://sunisthefuture.org
Any comments and suggestions are welcomed at sunisthefuture@gmail.com

Please also get into the habit of checking at these sites below for more on solar energy topics:

www.sunisthefuture.net

www.youtube.com/user/sunisthefuture

www.kiva.org/team/sunisthefuture

www.facebook.com/sunisthefuture

www.pinterest.com/sunisthefuture

HTML adl

Google+

Share

Copyright © 2011-2018 · Susan Sun Nunamaker All Rights Reserved · Sunisthefuture.net