An Introduction to Solar Panels and Solar Energy.
How does a solar system work? How are solar panels made? Here's a primer on solar energy from the world's largest solar manufacturer.
How Solar Works
Turn Your Roof Into a Power Plant
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You own the sun. Well, not exactly, but you do have the right to its power. Why not put it good use? With solar technology, you can turn your rooftop into a power plant. Here’s what you’ll need.
Most houses use AC power, but solar panels generate DC power. Enter the inverter: problem solved.
This allows the electricity to travel from the solar panels to the inverter and then into your house safely.
These elegant devices will sit on your rooftop and turn sunlight directly into electricity without noise or emissions. How cool is that?
(OPTIONAL) Want to go totally off-the-grid? Store your own electricity, consume it when you want to, and say goodbye to electric bills!
Plugging your solar system into the power meter means flexibility. When you're not using your solar electricity, you may be able to share with your neighbors and earn a credit from your local utility.
How Solar Panels are Made
How Solar Panels Are Made
From Sand to Sun
Learn how a humble bit of dirt attains the power to turn sunlight into electricity.
Sand: Humble Beginnings
Most solar panels produced today are made from Silicon, the second most abundant element on Earth and the primary ingredient in beach sand. The first step in making a solar panel is to create silicon ingots, giant blocks of high-purity (99.999999%) silicon.
To do this, we put hundreds of pounds of silicon chunks (i.e. rocks) into a giant crucible and add a little boron (called a ‘dopant’) to give the silicon positive polarity. Then, we cook it altogether at over 1,900 degrees Celsius!
Ingots & Wafers
We let the large silicon ingot cool down before slicing it into thin wafers using wire saws. Each fresh-cut silicon wafer is less than 200 microns thick – similar to a heavy piece of paper. These wafers must be carefully handled, inspected and cleaned before further processing.
The next step is to reduce the reflectivity of the wafer from about 30% to 10% through a chemical surface texturing process that creates tiny pyramids on the wafer’s surface. Now, when a photon (sunlight) hits the wafer's surface, it is more likely to be reflected into the wafer rather than back into space.
Solar Cells: From "Photo" to "Voltaic"
- N-TYPE SILICON
- FRONT ELECTRODE
- BACK ELECTRODE
- P-TYPE SILICON
It's time to turn our silicon wafer into something that converts sunlight into electricity. This is where the solar cell, the heart of a solar panel, is officially born. To do this, we first inject phosphorus into the silicon wafer at high temperatures. Then, we carefully clean the phosphorous off the rear surface and around the edges of the wafer.
Now we have a photovoltaic (photo = light, voltaic = energy; thus, “light into energy”) device! Next, we deposit metal contacts on the front and rear surfaces of the cell, allowing us to collect those electrons generated in the silicon. We also deposit a thin chemical layer on the cell's surface to further reduce its reflectivity from about 10% to 1%.
Solar Panel Assembly
To make a solar panel, we string together 48, 60, or 72 of our solar cells and lay them carefully within an encapsulant. We put high-transparency glass on the front surface and a highly durable, polymer-based backsheet on the backside. Then, we warm the whole stack (like a toasted solar sandwich) to create a protective cocoon around the solar cells.
Next, for structural stability and long-term protection, we place rigid aluminium frames around the perimeter, bonded together with a waterproof adhesive. Finally, we add a junction box to the back of the solar panel: an export terminal for our solar electricity. Now, the solar panel is ready for quality testing, packaging, and delivery.
Sun: Unlimited Energy
Once your solar panel is installed on your rooftop, sit back, relax, and let the sun save you money. Write a book, make coffee, or watch a football match on TV: you choose what to do with your solar electricity.
Furthermore, solar panels don’t have any emissions and they don’t make noise: they just sit their and do their job. Finally, take pride in the contributions you have made to combat climate change and to ensure a sustainable future for all.
History in the Making
The Global Solar Movement is Here
Solar energy is everywhere. You may not be able to dig a coal mine or oil well in your back yard, but with Yingli Solar panels you can harness nature’s highest source of power. The sun sends enough energy to Earth each hour to meet human energy demands for an entire year! It’s the world’s most abundant and accessible source of energy.
Perez, Richard, ASRC, University of Albany. As seen in: SHC 2008 Annual Report. International Energy Agency. March 2009. [Source]
Energy Resources of the World i
TERRA-WATTS PER YEAR*
- Natural Gas
Any serious, long-term global energy source must be scalable. Fossil fuels are generally supply constrained: as demand goes up, so do prices. With solar panels, it’s the exact opposite: as demand goes up, prices tend to go down!
The solar industry’s learning curve has been unprecedented. For the last 30 years, each doubling in global solar panel production and the declining cost of raw silicon have led to a roughly 25% reduction in solar panel prices!
How do we want to leave the Earth for our children? Silicon solar panels generate electricity without noise or emissions, and are comprised almost entirely of recyclable materials (like silicon, silver, and aluminum).
In addition, solar (photovoltaic) panels do not require water for operation, critically important for sustainable communities around the world.