In trying to come up with a topic to blog about, it dawns on me that it is always best to start with the basics. For the experts, this will seem pretty elementary. For the newcomers, I hope this helps shed some light on the wonderful world of solar.
Solar power is a pretty simple beast, disguised behind words like “photoelectric effect” and “solar irradiance”, which tend to intimidate most solar beginners. Most crystalline solar modules are made with similar construction: a matrix of crystalline solar cells strung together, sandwiched between either two layers of glass, or a layer of glass and a backsheet. Generally, a frame is attached to the module in order to make it easier to mount on various structures. The leads from the solar cells are strung through a junction box on the back of the module, and attached to cables to connect with other modules, or other electrical systems. It is the meat in our solar cell sandwich which performs the miracle of producing electricity.
The crystalline cell, whether mono or poly, is made from materials which create a current when exposed to sunlight. When the sun’s rays make contact with the solar cell, an electron jumps from one side to the other. The cells are wired together, so that when those electrons start moving, they are escorted out of the cell by way of our cables, thus creating electric current, or electricity.
By angling the face of the module perpendicular to the sun, you increase the power that the modules can output. For a fixed angle solar array, the optimal angle for year round production should be set to the locations latitude. For New York City, that means the optimal angle would be about 41°. Of course, to increase annual production, there are a variety of solar trackers that are either automatically or manually adjusted to maintain a better angle towards the sun.
Now, due to a battle lost by Thomas Edison years ago, the electricity used in our homes by our lights and appliances, is Alternating Current (AC) electricity. The power produced by our solar modules is in the form of Direct Current (DC) electricity. In order to convert the electricity from DC to AC, we run it through an inverter so that the power can be used by our homes and businesses. With the use of net-metering, all excess electricity not immediately used is pumped back into the local grid, or stored in a battery bank to be used at a time when the solar modules are not producing enough power to supply the demand.
As our blog “The Sundial” progresses, we aim to delve deeper into the world of solar power. While the technology that crystalline solar modules are based on has been mostly unchanged for many years, the intricacies of the solar economic climate, as well as details in module production can largely influence the overall economics and longevity of every solar installation. As we peel away the surface, we hope to enlighten our readers as we near the core of the issues.
**All solar puns, though maybe not humorous or clever, were entirely intentional.