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.
In fact they are counting on it, as the very cost justification is based on a certain long life. In reality solar cells do last for decades but their efficiency does not necessarily stay the same of over time. Heat and corrosion can impact their performance depending on the design and material used.