Different solar panels vary in efficiency, but the technology is well-developed, with panels reliably producing power for over 25 years. As with any technology, performance will gradually decline over time, though this decrease will differ depending on the type and quality of the. There are a number of key factors that affect solar efficiency, including panel type, placement, climate, inverter efficiency, panel age, electricity demand match, shading intensity, and soiling. Solar panel type is one of the biggest factors affecting efficiency. But efficiency is only part of the story. Want to get a better understanding of why? We go into more detail below. Age-related wear and tear Like anything else, solar panels experience a bit of wear and tear as they age.