By using even a brief personal story, Mead is helping her readers relate to her and open to her viewpoint. Her mentors and teachers instilled in her a sense of purpose — an urgent one, at that — to study human behavior as it happens naturally in a variety of societies and cultures. We can all relate to the feeling of longing for a sense of purpose, even though we may not have an interest in anthropology specifically. Most of us will nod knowingly at her decision because we understand that when one finds a sense of purpose, the will to make it happen follows strongly.
Future ultracapacitors could have an energy density higher than 60 Wh/kg along with a power density greater than 100 kW/kg. Such is from a MIT study on ultracapacitors for future cars, implied here . That would be up to + TJ of electrical energy stored per 1000 metric-tons of ultracapacitors, able to be discharged at a rate of + TW. For example, a 100,000-ton warship with just 5% of its mass as ultracapacitor banks could store a terajoule, then discharge it at a rate of half a terawatt. Technology of the distant future may be superior, but the preceding is a reasonable lower limit. Energy storage is not the only limiting factor, though.