There are three primary types of residential solar panels. These are monocrystalline, polycrystalline, and thin film panels. When choosing one for your home, one determinant of your decision should be the power ratings of the panel.
Apex Solar Solutions and other solar energy companies explain wattage is the amount of electricity the panel can generate when working under industry standard test conditions. Apart from wattage, here are the other ratings you should consider when buying a panel for your home:
Cell efficiency refers to the amount of sunlight that is converted to electricity. There are two ways to increase the electricity output of solar panels. You can increase the number of bulbs or the efficiency of your cells. Increasing the bulbs in your panel is ideal if you have ample space on the roof. You can alternatively opt for higher bulb efficiency if your roof area is inadequate. Look for cell efficiency ratings of 15-18%.
Though you require sunlight for your panel to function well, too much heat will make your panels produce less electricity. Temperature co-efficient rating is the decrease in electricity production for each temperature increase above the STC rating. Most panels have a 0.4% rating, meaning 0.4% decrease for each one-degree rise above their rating. While this may not seem significant, a 275-watt panel produces no more than 260 watts on a 1020F day.
This refers to the variation of your panel from the actual wattage it should produce under its STC rating. It ranges from +/- 5 watts for most panels. The less your deviation from the STC rating, the more electricity your panel will produce.
You get two warranties for your solar panels. These are a production guarantee and a manufacturing warranty. The manufacturing warranty guarantees your panel will generate electricity for a specific period. Your production guarantee states the amount of power the panel will generate annually.