It can be difficult to purchase a solar panel. A panel's specifications can be confusing. On a specification sheet for a solar panel, there are many numbers as well as industry standards. These numbers and industry standards may not be relevant for the average consumer. If you need to buy a solar panel, it's a good idea to understand how they work so that you can decide which one is right for you.
There are two types of ratings that are important to understand. The first is the STC rating. This is a test that determines the maximum power output the panel can produce under standard test conditions. The cell temperature is 25° Celsius in the STC test conditions. The test conditions are designed to simulate 1,000 W/m2 of incoming light. For every degree of temperature increase, the panel's peak rating drops by a percentage. 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 was popularized by the California government, which tested panels. PTC rating is used primarily for real-world temperature. Calculating the PTC rating was initially difficult. California's government improved the process and can now forecast output more accurately. In most cases, there is a 6% difference between the nominal rated and nominal power. Some panels may have negative power tolerances.
The short circuit current is an important specification. This is how much current the panel can generate when a cell shorts. This can be measured by touching two wires together. It's an important feature to have because it ensures that a panel is safe to use. The maximum current is measured in watts. A panel that is wired in series will produce the same wattage as a parallel panel.
The voltage at maximum power point is an important aspect of solar panel specifications. This is also called the current at maximum power point. The voltage at maximum power points is often equal to the nominal. The voltage at the maximum power point will vary from solar panel to solar panel depending on the amount of sunlight. The output of the panel will be greater if it is voltage higher than the maximum power. If the panel's maximum power is less than its nominal power, it will not be able to produce as much energy as it can at its maximum power.
It is important to consider the efficiency of your solar panel. The panel's efficiency measures how much light is received by it. The W/m2 is the most common measurement of efficiency. The panel absorbs more light if it has a higher efficiency.
Solar panels are also rated to withstand wind pressure. Panels can support loads up to 5,000 pascals. This is equal to about 2-4 feet of snow. The type of snow used and the snow density affect the rated snow amount. The majority of panels come with a warranty of at most ten years. The warranty will also tell you how long the manufacturer expects the panel's to last. If the company goes out business or discontinues production of the panel, the warranty becomes null.