Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×
Power Hardware

MIT Unveils Sun-Free Photovoltaics 103

An anonymous reader writes "Researchers at MIT just unveiled a new solar power generator that doesn't need sunlight to function. The button-sized power generator can tap energy from heat, the sun's rays, a hydrocarbon fuel, or a decaying radioisotope, and it can run three times longer than a lithium-ion battery of the same weight. It is hoped that the technology may one day be used to generate power for spacecraft on long-term missions where sunlight may not be available."
This discussion has been archived. No new comments can be posted.

MIT Unveils Sun-Free Photovoltaics

Comments Filter:
  • by dhj ( 110274 ) * on Friday July 29, 2011 @02:40PM (#36925962)

    Good point... The summary left off an important bit of information from TFA:

    "Based on that technology, MIT researchers have made a button-sized power generator fueled by butane that can run three times longer than a lithium-ion battery of the same weight; the device can then be recharged instantly, just by snapping in a tiny cartridge of fresh fuel"

    So... using this to convert butane to electrical energy it lasts three times longer than a lithium-ion battery of the same weight.

    But if you look at energy density of the two fuel sources: http://en.wikipedia.org/wiki/Energy_density [wikipedia.org]

    You find that butane/propane/gas/diesel is about 45 megajoules / kg and Li-ion batteries store about 0.75 megajoule / kg. Converted energy 2.25 megajoules (3x Li-Ion) out of stored energy 45 megajoules = 5% efficiency rate converting butane heat to electrical energy using this device.

    --David

"If truth is beauty, how come no one has their hair done in the library?" -- Lily Tomlin

Working...