Yes. The crystalline silicon cells degrade slightly over time due to exposure of UV light. This happens at a rate of about .4% per year. Panels now carry a linear warranty, meaning they are guaranteed not to degrade more than this amount per year for 25 years. All of our financial models take this degradation into account. Plus, solar is still considered to be an appreciating asset of real property due to the average annual increase in national power rates of 5%.