The price acts as a ceiling to keep costs low and would fall slowly over the 20 - year life of the system. (sciencemag.org)
Under these conditions, Aurora revealed that it would take just under the full 25 - year life of the system to recoup the upfront cost! (blog.aurorasolar.com)
That means that the human hierarchy is characteristically of an emotional - intellectual nature, instead of physical - emotional nature like the animal hierarchy, while the consummation of the emotional - intellectual level, represented by image, social position, reputation, is the one that can provide the necessary energy for the interdependent life of the systems. (globaleducationmagazine.com)