When exploring solar solutions for small-scale applications, one common question arises: how many watts does a 10 cm solar panel have? Typically, these compact panels generate between 0. 5W under standard test conditions (STC), depending on material efficiency and sunlight exposure. Let's. The formula to calculate the Solar Panel Power is: [ text {Solar Panel Power} = text {Length} times text {Width} times 0. Let"s break down the factors affecting performance and why these miniature power sources are gaining traction across industries. 6 inches thick, weighs 40–55 lb, and produces 350–460 watts. Portable 100 W panels are about 42 × 21 inches. Over a sunny day, it can make about 1.