Solar panels degrade — they produce less electricity each year as cells age. This is normal, expected, and accounted for in manufacturer warranties. The question is: how much, and how fast?
Budget Tier 1 panels (JA Solar, Jinko, Risen) typically degrade at 0.5% per year. After 25 years, they still produce about 87–88% of their original output.
Premium panels (REC Alpha, SunPower Maxeon) degrade at 0.25–0.30% per year. After 25 years, they produce 92–93% of original output.
That 5% difference might sound small, but over 25 years it adds up to meaningful kWh — and meaningful savings. A 5 kWp premium system in Year 25 produces approximately 28 kWh more per month than an essential tier system. At projected Meralco rates in 2051, that’s a significant amount.
The other factor is the product warranty itself. Essential tier: 10–12 years. If a panel fails in Year 14, you’re outside warranty. Premium tier (REC): 25-year product warranty. SunPower: 40 years. This is not just a marketing number — it’s the manufacturer’s commitment to replace defective panels for that period.