Editing Space elevator (section)

===Powering climbers===
Both power and energy are significant issues for climbers – the climbers would need to gain a large amount of potential energy as quickly as possible to clear the cable for the next payload.

Various methods have been proposed to provide energy to the climber:
* Transfer the energy to the climber through [[wireless energy transfer]] while it is climbing.
* Transfer the energy to the climber through some material structure while it is climbing.
* Store the energy in the climber before it starts – requires an extremely high [[specific energy]] such as nuclear energy.
* Solar power – After the first 40&nbsp;km it is possible to use solar energy to power the climber<ref>{{cite web |last1=Swan |first1=P. A. |last2=Swan |first2=C. W. |last3=Penny |first3=R. E. |last4=Knapman |first4=J. M. |last5=Glaskowsky |first5=P. N. |title=Design Consideration for Space Elevator Tether Climbers |url=http://isec.org/pdfs/isec_reports/2013_ISEC_Design_Considerations_for_Space_Elevator_Tether_Climbers_Final_Report.pdf |url-status=dead |archive-url=https://web.archive.org/web/20170116175959/http://isec.org/pdfs/isec_reports/2013_ISEC_Design_Considerations_for_Space_Elevator_Tether_Climbers_Final_Report.pdf |archive-date=16 January 2017 |publisher=[[International Space Elevator Consortium|ISEC]] |quote=During the last ten years, the assumption was that the only power available would come from the surface of the Earth, as it was inexpensive and technologically feasible. However, during the last ten years of discussions, conference papers, IAA Cosmic Studies, and interest around the globe, many discussions have led some individuals to the following conclusions: • Solar Array technology is improving rapidly and will enable sufficient energy for climbing • Tremendous advances are occurring in lightweight deployable structures.}}</ref>

Wireless energy transfer such as [[laser power beaming]] is currently considered the most likely method, using megawatt-powered free electron or solid state lasers in combination with adaptive mirrors approximately {{convert|10|m|ft|abbr=on}} wide and a photovoltaic array on the climber tuned to the laser frequency for efficiency.<ref name="Edwards" /> For climber designs powered by power beaming, this efficiency is an important design goal. Unused energy would need to be re-radiated away with heat-dissipation systems, which add to weight.

Yoshio Aoki, a professor of precision machinery engineering at [[Nihon University]] and director of the Japan Space Elevator Association, suggested including a second cable and using the conductivity of carbon nanotubes to provide power.<ref name="JapanUKTimes" />