Buying a solar panel can be a confusing process. You may also find it difficult to understand the specifications. There are many numbers, industry standards and other information on a sheet of specifications for solar panels. These numbers and industry standards aren't relevant to the average customer. It's important to learn how solar panels work before you buy one.
It is important to be familiar with two types rating. First, there is the STC rating. This test is used to determine the maximum power output for the panel under standard conditions. Under STC test conditions, the cell temperature is 25 degrees Celsius. The test conditions simulate 1,000 W/m2 light. The panel's peak rating will decrease by a percentage with increasing temperature. A panel with a higher STC rating will have a higher peak output, which is ideal for generating more power.
The PTC rating is a newer standard for predicting panel output. It became popular as the California government tested panels. The PTC rating is used mainly for real-world temperatures. The PTC rating was initially complicated to calculate. California government has since refined the process which allows for better output forecasting. In most cases, there is a 6% difference between the nominal rated and nominal power. Some panels may have negative power tolerances.
Another important specification is the short circuit current. This is the maximum current a panel can deliver when a short circuit occurs. It is done by touching both wires together. It is important to have this feature because it assures panel safety. The maximum current is measured by watts. If a panel has been wired in series, its maximum output wattage will be the exact same as if wired in parallel.
The voltage at maximum power point is an important aspect of solar panel specifications. This is also known simply as the current maximum power. The nominal power is equal to the voltage at the maximum point. Depending on the amount of sunlight, the voltage at maximum power point can vary from one panel to another. The output of a solar panel will be higher if the maximum power point voltage is higher. The panel will not produce the same amount of power if the maximum powerpoint is lower than its nominal power.
The efficiency of the solar panel is also important. The efficiency of the solar panel refers to the amount of light irradiance the panel receives. The efficiency of a panel is usually expressed as W/m2. The higher the efficiency, the more light the panel can absorb.
Solar panels are also rated to withstand wind pressure. The panels can withstand a load of around 5,000 pascals. This is equal to about 2-4 feet of snow. The type of snow and its density determine how much snow is rated. Panels usually have a warranty for at least ten to fifteen years. It will also state how long the manufacturer expects that the panel will last. If the company closes down or ceases production, the warranty is null.