Stuart Mcmillen
Energy slave - surplus energy on top of base bodily metabolism which a man could expend as work → 250 eight-hour working days → annual unit of work
work still being performed under the command of humans, but the work was no longer being channelled through human muscles.
Solar income
Coal, oil and gas were ancient batteries for ancient sunshine that allowed civilisation to live beyond its solar income.
Energy return for energy investment on oil - now it’s 4:1
Energy Scavenging for Mobile & Wireless Electronics