Enteroendocrine cells of the intestine are the most numerous endocrine cells of the body. In a sense they are known to act as chemoreceptors, initiating digestive actions and detecting harmful substances and initiating protective responses.
The typical manufacturer's warranty on a solar panel is 25 to 30 years, but panels can last up to 40 years with care and attention.
As for me, if the Solar Panels deliver their worth in less than 3 years, it would be well worth it. The 25-30 year warranty seemed to be unrealistic especially for Chinese manufactured panels, very few companies will survive that long.