How Does Solar Power Work?
October 22, 2011, Submitted by: Ken Tweet
Solar Energy: Keeping it simple
The Earth constantly basks in the Sun and is absorbing enough energy to satisfy the world’s power needs many times over.
So how do we turn the Sun’s energy into electricity? Well, the light from the sun contains energy. These particles of energy are called ‘photons’. These photons are created deep in the Sun by the fusion of atoms, and once they reach the sun’s surface, they shoot out in all directions into space. They take about 8 minutes to reach us here on Earth. You can feel them as they warm you when you stand in the sunlight.
When sunlight hits an object, that energy generally turns into heat. However, when sunlight hits certain materials, the energy turns into a flow of electricity instead. It’s kind of like turning on a water hose – imagine that the water in the hose is the flow of electricity.
Crystals made out of silicon will produce an electrical current (like the water flow in a hose) when exposed to sunlight. What happens is, the electrons that are in the silicon begin to ‘move’ when struck by light (instead of just staying mostly in place). Since the electrons move, we can harness that flow and direct it to useful things such as being converted to the energy we use in our homes, or perhaps to charge a bank of batteries.
In slightly more detail, a silicon atom contains electrons spinning around it’s nucleus. In a silicon crystal (of many silicon atoms), the bonds between the silicon atoms are made of electrons that are shared between all of the atoms of the crystal itself. When the light gets absorbed, one of the electrons that is in one of the bonds gets ‘excited’ up to a higher energy level and can move around more freely than when it was bound. That electron can then move around the crystal freely, and we can get a current. This is multiplied many times over since the crystals are made up of many atoms.
The Silicon Atom
The silicon atom has three shells (the three ellipses around the nucleus). As silicon atoms come close to one another they connect, latching onto the electrons in the outer shell of other atoms to form a silicon crystal.
Newer materials than silicon use smaller and cheaper crystals, such as copper-indium-gallium-selenide, that can be shaped into flexible films. One drawback though is this ‘thin-film’ solar technology is not as good as silicon at turning light into electricity.
Solar panels are made from these silicon semiconductor materials (and the newer thin-film materials). Solar panels come in a variety of sizes and electrical capabilities. This aids in the design of a wide variety of purposes and provides the flexibility to customize most any energy system.
Power from the Sun: A Practical Guide to Solar Electricity
Here is an example of a small solar panel
Instapark® 5W Mono-crystalline Solar Panel with 12V Solar Charge Controller
Here is an example of a large solar panel
Grape Solar CS-P-270-DJ 270 Watt Polycrystalline PV Solar Panel
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Nice simplified explanation. People seek out how things work and this shows it with solar power. These panels are getting smaller and more efficient each year, and cheaper like computers. Decades ago solar power was more expensive and the panels were bigger because they did not gather as much electric current as they do now. Plus the wonderful Chinese can mass produce anything cheaply, yeah at the cost of good American jobs. At least survival equipment is not as costly as it once was.
http://www.nytimes.com/2011/10/22/business/global/china-warns-of-bad-effects-if-us-turns-protectionist.html?partner=rss&emc=rss Here is something interesting about solar panels and dear CHINA upset, “OH poor China”. It seems like the Chinese manufactures everything for the U.S. that should be made in the U.S. People just have no idea what China’s military looks like, just waiting for the day…………….
Cant wait till the whole spectrum of light is able to be collected by a solar PV panel… At the moment only a small fraction of light is actually able to be converted into electrical energy…
I’m still looking for a smaller roll up panel that will be cheap enough to buy for charging up a laptop battery or small SLA battery for inverter use, however still maintain some quality and reassurance that it will work a few years after I buy it!
The kicker is that only around 1 kilowatt is available from 1 square metre of “air” at a prescribed level. This figure greatly depends on your earthly location and the ambient ‘air conditions.
Solar conversion will only ever achieve maximum of 30% efficiency – around 350 watts per square metre.(right now the domestic solar panel is around 11%. Don’t let those mealy mouth sales turkeys tell you otherwise)
The real benefits will come from tools and appliances that use less power for more results.
The big three. Heating, Cooking and cooling will be never achievable except in some appropriate locations to a small minority.
Alternative energy sources will only be useful to those tech savvy people like Ken and others who will know how to effectively use their installations.
I have been in the low power voltage power industry for 40 years. I haven’t bothered to wire up my house for alternate energy sources even though I have access to much second hand or new parts and the know how to do this. The economies of scale do not justify the effort or cost.
In a survival situation though – that’s a different story.
@ Ken, Nice piece, good of you to take the time. Thank you for the continued education, hope all is well.. Survive-Alll… “you are posting comments too quickly ?” huh?…