A 500-watt solar panel has a wattage rating of 500 watts under Standard Test Conditions (STC). STC is an industry standard that involves testing panel performance in a lab under 1,000 lumens/m2of light, and at a temperature of 77°F (25°C). It indicates the power output you can expect. A lot of innovative solar technology is utilized to achieve a solar panel rating of 500 watts. Here are two technologies that are commonly used when producing these modules. 500-watt solar panels are designed for larger solar power installations. They can be found in setups such as: 1. Utility-scale solar farms 2. Commercial jobs 3. Ground-mount systems 500-watt solar panels are generally made with 144 half-cut monocrystalline cells. The typical footprint of a single 500 W panel is about 27.5 square feet (7.40 feet x 3.72 feet). In terms of. 500-watt solar panels have their place, but it is generally not on the roof of your home. Their size and weight make them less practical to install in most residential solar situations, nor are.