Editing Fusion power (section)

=== Fuel reserves ===
Fusion power commonly proposes the use of deuterium as fuel and many current designs also use [[lithium]]. Assuming a fusion energy output equal to the 1995 global power output of about 100 [[exa-|E]]J/yr (= 1 × 10<sup>20</sup> J/yr) and that this does not increase in the future, which is unlikely, then known current lithium reserves would last 3000 years. Lithium from sea water would last 60&nbsp;million years, however, and a more complicated fusion process using only deuterium would have fuel for 150&nbsp;billion years.<ref>{{cite web |title=Energy for Future Centuries |url=http://www.agci.org/dB/PDFs/03S2_MMauel_SafeFusion%3F.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110727135814/http://www.agci.org/dB/PDFs/03S2_MMauel_SafeFusion?.pdf |archive-date=July 27, 2011 |access-date=June 22, 2013}}</ref> To put this in context, 150&nbsp;billion years is close to 30 times the remaining lifespan of the Sun,<ref name="sunlife">{{cite web |last=Christian |first=Eric |display-authors=etal |title=Cosmicopia |url=http://helios.gsfc.nasa.gov/qa_sun.html#sunlife |url-status=dead |archive-url=https://web.archive.org/web/20111106095009/http://helios.gsfc.nasa.gov/qa_sun.html#sunlife |archive-date=November 6, 2011 |access-date=March 20, 2009 |publisher=NASA}}</ref> and more than 10 times the estimated age of the universe