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.
A roof top solar system has no moving parts, so it has a long expected lifetime exceeding 25 years (used in this example). 1  However inverters (which convert the panel DC current into AC) have an expected lifetime of 10 to 15 years. In our example we add the cost of a replacement inverter to the system after 12 years.