Most 200-watt solar panels on the market today measure roughly 3.5 to 4 feet long by 2 to 2.5 feet wide. Thickness is usually around 1 to 1.5 inches. Exact dimensions can vary between manufacturers and models based on cell configuration, but on average a 200-watt panel occupies approximately 7 to 10 square feet of area. Actual sizing numbers should be confirmed for any solar panel purchases, as capacity and dimensions must be balanced when designing a solar array installation.
Cell Type and Arrangement
Solar panel construction starts with the arrangement of the dozens of individual solar cells inside that do the actual energy conversion. Two main categories of cells are used: monocrystalline and polycrystalline silicon cells. The size and spacing requirements of these cells, as well as the internal circuitry channels, establishes the panel area for a given wattage rating. Higher density cells and more efficient internal wiring allows some panels to achieve a target wattage with a smaller footprint.
Voltage and Current
Along with watts, voltage and current ratings help determine solar panel sizing. Power (watts) equals voltage multiplied by current. So a panel might produce 36 volts at 5.56 amps to reach 200 watts. Both voltage and current levels have minimum cell sizes and spacing requirements. And optimizing these variables for RV and off-grid usage often results in a standard nominal 12-volt operation, which comes at the expense of having larger surface areas for 200+ watt panels.
Encapsulation Materials
Solar cells require weatherproof encapsulation using transparent materials like tempered glass or high-transparency plastics. The mechanical framing and thickness required, as well as internal space for weather sealing materials, adds significantly to panel thickness and weight. Thinner, prettier panels can require more advanced, costlier encapsulation to achieve comparable durability. These factors represent engineering tradeoffs between panel size, rated power output, and cost.
Panel Frame and Junction Box
The external aluminum frame and junction box on the back of a solar panel where connections are made also take up a measurable portion of the total area, in some cases up to a few additional inches per side. More compact junction boxes help minimize wasted space. Premium frames often provide increased stiffness without much added weight or thickness, but even then overhang the panel area slightly.
Temperature Effects
Solar panel output decreases as temperatures increase. Manufacturers thus often rate panel capacity based on an assumed 77°F operating temperature. Colder ambient conditions allow 200+ watt ratings from physically smaller sizes, with such temperatures rarely seen in most applications. Adding to a panel’s surface area helps them maintain stated outputs in hotter field conditions.
Mobility and Aerodynamics
For marine, vehicle, and transportable off-grid solar panel applications, both low weight and wind resistance are beneficial. Encapsulation materials, framing, and junction boxes can all be engineered with mobility in mind, though often at increased cost. Small and rugged 200-watt panels built for portability do exist, but typically run $300 and above.
Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as a Solar Electrical Engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.