Solar Panel Wattage Explained: How Many Watts Do You Need?
Most residential solar panels fall into the 250W to 450W range, depending on the technology and manufacturer. But though commercial systems may use panels exceeding
About 97% of home solar panels installed in 2025 produce between 400 and 460 watts, based on thousands of quotes from the EnergySage Marketplace. But wattage alone doesn't tell the whole story. In fact, efficiency matters more than wattage when comparing solar panels—a higher wattage can simply mean that a panel is larger.
Solar panel power output can get confusing fast. Is 400 watts good? 420 watts? Should you opt for the 450-watt panel? Is it worth the extra cost? About 97% of home solar panels installed in 2025 produce between 400 and 460 watts, based on thousands of quotes from the EnergySage Marketplace.
Wattage refers to the amount of electrical power a solar panel can produce under standard test conditions (STC), which simulate a bright sunny day with optimal solar irradiance (1,000 W/m²), a cell temperature of 25°C, and clean panels. In simpler terms, a panel's wattage rating tells you its maximum power output under ideal conditions.
Some panels' high power output rating is due to their larger physical size rather than high efficiency. If two solar panels have 20% efficiency ratings, but one has a power output rating of 350 watts and the other is rated at 400 watts, all that means is that the 400-watt panel is about 14% larger than the 350-watt panel.
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