Install Solar
The sun is ultimately the major source of energy on this planet, and solar and wind generators and products are no longer scientific wonders or expensive toys. We provide a range of high quality excellent value solar modules and mini panels, as well as a range of solar chargers, batteries, lights, fans and other accessories.
Solar cells come in a number of varieties and it is important to understand what you are buying. It is also important to note that the peak voltage and current or power figures apply only for a small part of the day, and that efficiency and voltage tends to drop with increasing temperature. Also in the morning and afternoon the sun may strike the solar panel at a shallow angle, and the season and latitude also affect this angle of incidence. At an angle of 30° a panel only receives half the energy it does when the sun hits it at 90°.
Furthermore, when specifying a panel it is also necessary to take into account the fact that the voltage drops under load - e.g. for 12 volts under load, a panel with a maximum voltage of 15.2 volts would be necessary, and for high currents/wattages (e.g. 50W up) a 17 volt panel plus regulator is recommended. In fact, using a panel without a regulator tends to halve the life of both the panel and the battery!
Amorphous cells do not have a well defined crystalline structure and are in general the cheapest and the least efficient - utilizing only 5 to 7% of the solar energy that strikes them. But some of the most expensive panels are flexible ones based on amorphous cells. Allow twice the area you would for a good crystalline technology.
Multicrystalline and nanocrystalline panels have only slightly better efficiency of 7 to 8% due to the smallness of the crystals - do not confuse these with the polycrystalline and monocrystalline type which are typically around twice as efficient.
Monocrystalline cells have carefully grown large crystals of high purity for which we pay a considerable premium. For larger panels (5 Watts and up) we tend to prefer the monocrystalline crystals and note that with falling prices, the cost of shipping and installation of these larger panels tends to dwarf the savings from using a lesser technology.
Polycrystalline panels provide the best tradeoff between price and efficiency - large but irregularly shaped crystals can be seen in these panels which provide an efficiency of 13 to 15%. In general, the smaller minipanels and chargers we sell (below 3 Watt) are polycrystalline. Our large 120W panels have high quality low loss glass to maximize the solar energy that reaches the panel - we challenge you to find a better panel at a better price!
|