Buyers should prioritize the Start-up Wind Speed, which should ideally be ≤2.5 m/s to ensure energy generation in low-wind conditions. Additionally, evaluate the Rated Power vs. Peak Power to understand actual output; look for turbines with MPPT (Maximum Power Point Tracking) controllers to optimize efficiency. For rooftop installations, Vertical Axis Wind Turbines (VAWT) are often preferred over horizontal ones due to their lower noise levels (<45dB) and ability to capture wind from any direction without a tail mechanism.