Scratches or breakages of any kind can lead to output degradation, and even more technically, the way solar panels are wired internally and externally (to the inverter) can lead to decreased output as well, a problem that typically arises in the manufacturing or installation. Scratches or breakages of any kind can lead to output degradation, and even more technically, the way solar panels are wired internally and externally (to the inverter) can lead to decreased output as well, a problem that typically arises in the manufacturing or installation. Summary: Photovoltaic (PV) panels are essential for renewable energy systems, but their slow discharge rates often puzzle users. This article explores the science behind this phenomenon, factors affecting discharge speed, and practical solutions for optimizing solar energy storage. The Science. Normal degradation is 0. 8% annually: Quality solar panels naturally lose efficiency over time, so a system producing 10,000 kWh in year one should generate around 9,950 kWh in year two – this gradual decline is expected and warranty-covered. Inverters are the weakest link in solar systems: With. When people hear that solar panels produce slightly less electricity each year, the immediate assumption is that it's due to damage. Discharging begins when those batteries release stored energy to power your appliances when sunlight is unavailable. When we use high-energy-consuming devices such as air conditioners or heaters, the battery gets drained faster.