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.
It is wonderful that solar industry is growing exponentially and many conscientious educators and scientists of our planet are all working together to ensure us earthlings to have a smooth transition into the Renewable and Clean Energy Age. I cannot emphasize enough that Sun Is The Future for human kind for its abundance/availability, cleanliness, safety, and the fact that it is free. This next clip by Hilaroad will take us from the elemental stage of silicon to the completion of solar module/panel. The explanations are succinct and clear. Once you’ve completed viewing the clip, feel free to go over it again for better recall.
http://www.youtube.com/watch?v=Caf1JIz4X2I&feature=related or click below:
Now, please look over these questions below. If you are uncertain about any of these questions, please feel free to go over the clip again for better understanding or recall.
1. Object at right angle to sun’s rays is receiving energy at approximately the rate of _____J/sec/m2 ?
2. Solar cell manufacturers use_____crystal to make solar cell ?
3. How many valence electrons are there in a silicon atom ?
4. Which elements can be added to silicon, according to this clip ?
5. What are N-layer and P-layer of a photovoltaic cell and how are they created?
6. _____energizes electron in N-layer and attracted through a conductor to P-layer ?
7. What is the negative and positive terminal of the solar cell ?
8. How do you produce higher voltage and current using solar cells?
Posted by sunisthefuture-Susan Sun Nunamaker, sunisthefuture@gmail.com
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.
Yes, I have more in store for you! Here is the third episode of our discussion on “What Is Solar Cell”.
Now, to help refresh our memory of an earlier presentation and demonstration on March 10, 2011, “How Do You Measure the Power Produced by Solar Cells”, please recall that in a series circuit, the current through each of the components of the circuit is the same, voltage across the components is the sum of the voltages across each component. Whereas for a parallel circuit, the voltage across each of the components is the same and the total current is the sum of the current through each component. Please feel free to refer to the post on March 10, 2011, for diagrams of these circuits. Keep in mind that additive voltage results when solar cells are connected in series while higher current results when connecting solar cells in parallel.
Our next clip is at http://www.youtube.com/watch?v=B8zEBrH2bPU&feature=related or simply click below:
Keep in mind that solar modules/panels may be interconnected in series or parallel or both to create an array with the desired peak DC voltage and current.
More will continue in “What Is Solar Cell (4)”. Please feel free to leave your comments, questions, or email me at sunisthefuture@gmail.com
Remember we are all working together toward a better and brighter tomorrow!
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.
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.
Excellent question from more than one of our readers: How Do You Measure the Power Produced by Solar Cells ?
To set the stage for our following two film clips, please allow me to explain what a multimeter (or multitester) is: it is an electronic measuring instrument that combines several measurement functions (measuring voltage, current, and resistance) in one unit. Multimeters are available in a wide range of features, precisions, and prices, anywhere from less than US$10 to more than US$5,000. To find out how much the power is produced by solar cells, we need to know the voltage and current produced and the fact that power equals to the product of voltage multiplied by current.
voltage (unit of measurement is volt, V): electrical driving force, energy per unit charge, electrical potential difference between two points
current (unit of measurement is ampere, A): rate of flow of electric charge ( carried by moving electrons in a conductor such as wire or in an electrolyte carried by ions, or in a plasma by both)
resistance (unit of measurement is ohm, Ω): measure of the degree to which an object opposes an electric current through it
power (unit of measurement is watt, W): power is the rate at which work is performed or energy is converted. In direct current resistive circuits, electrical power is calculated using Joule’s law. In the case of resistive (Ohmic or linear)loads, Joule’s law is combined with Ohm’s law (I=V/R)
such that R represents numerical value of ohm or resistance, I represents numerical value of ampere or current, V represents numerical value of volt or voltage, P represents numerical value of watt or power
Joule’s law: P= VI, so solar cell or solar module measured at 2V and 1A would produce power at 2W, solar cell or solar module measured at 3V and 2A would produce power at 6W, solar cell or solar module measured at 2V and 1mA would produce power at 2mW (note: mA=0.001A or mA means milliA)
Joule’s law + Ohm’s law: P=(I2)R=(V2)/R
series circuit:
Series Circuit
the current through each of the components of the circuit is the same, voltage across the components is the sum of the voltages across each component
parallel circuit:
Parallel Circuit
the voltage across each of the components is the same and the total current is the sum of the currents through each component
