A square meter of solar panels can generate between 150 to 300 watts of electricity under optimal conditions, depending on the efficiency of the solar cells used. Generally, modern solar panels usually have efficiencies ranging from 15% to 22%. Solar panels have become a cornerstone of renewable energy, but many wonder: How much power can a single square meter of solar panels actually produce? Let's break down the science behind photovoltaic efficiency. 1 (calculated based on. On a clear day, each square metre of the Earth's surface receives approximately 1,000 watts of solar energy, also known as 1 kW/m². Factors influencing energy generation include location, sun exposure, and panel.