It can be difficult to purchase a solar panel. It can also be difficult to understand the specifications of a panel. The specification sheet for a panel can contain many numbers and industry standard information. These standards and numbers are not applicable to the average consumer. It is important that you understand how solar panels operate before you make a decision about which one to buy.
It is important that you understand two types ratings. First, there is the STC rating. This is a test to determine the maximum power output of the panel under standard test conditions. Under STC testing conditions, the cell temperature can be set at 25 degrees Celsius. The conditions were created to simulate 1,000 W/m2 infrared light. The panel's peak rating will decrease by a percentage with increasing temperature. A panel with higher STC ratings will produce higher peak output which is great for producing more power.
PTC Rating is a more recent standard for predicting panel output. It gained popularity as California's government began testing panels. PTC rating can be used to determine real-world temperatures. It was difficult to calculate the PTC rating at first. The California government has since improved the process, which allows more accurate output forecasting. The difference between nominal and rated power is usually 6%. However, some panels will have negative power tolerances.
Another important detail is the short-circuit current. This is the maximum current the panel can output when the cell short circuits. This is measured by touching the two wires together. This feature is vital because it makes sure that the panel is safe to be used. The maximum current measured in watts is the total. If a panel is wired together, its maximum wattage output will not change from if it were wired parallel.
Another important solar panel specification is the voltage at the maximum power point. This is also known by the current to the maximum power. The voltage at maximum power points is often equal to the nominal. Depending on how much sunlight is available, the voltage at the maximum powerpoint will vary from one solar panel to the next. The output of a panel is proportional to the voltage at its maximum power. If the panel's maximum output is lower that its nominal power, it won't be able produce as much power.
It is important to consider the efficiency of your solar panel. The panel's efficiency is the amount of light irradiance received by it. The efficiency is often expressed in W/m2. The panel absorbs light more efficiently.
Solar panels can also be rated for resistance to wind pressure. Panels can support loads up to 5,000 pascals. This amount of snow is approximately 2 to 4 feet. The type of snow used and the snow density affect the rated snow amount. Most panels come with a minimum ten-year warranty. The warranty will indicate the expected performance of the panel. The warranty will be worthless if the company goes out of business or has to discontinue production of the panel.