# Free electricity from air **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [May 25, 2023, 4:30am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556 "2023-05-25T04:30:19Z")\ **Posts on this page:** 14\ **Page:** 2
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [June 1, 2023, 7:13am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/21 "2023-06-01T07:13:13Z")
> [@Thudlow\_Boink](#): > > Where hydrogen is built into helium at a temperature of millions of degrees? Exactly so. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [June 1, 2023, 1:37pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/22 "2023-06-01T13:37:17Z")
They’re getting ~microwatt per square centimeter for a single sheet, albeit with a material not optimized for this application. And they think it’s stackable. But don’t expect to run your walkman off it any time soon. ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [June 1, 2023, 9:43pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/23 "2023-06-01T21:43:46Z")
One microwatt per square centimeter works out to one watt per 10 square kilometers. I think I might be able to get more power from rubbing a balloon on my hair. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [June 1, 2023, 9:53pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/24 "2023-06-01T21:53:27Z")
> [@Kent\_Clark](#): > > One microwatt per square centimeter works out to one watt per 10 square kilometers. No, it doesn’t. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 1, 2023, 11:51pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/25 "2023-06-01T23:51:38Z")
I recall energy scavenging/harvesting was a big topic a decade two ago. Basically, it was the belief that sensors could be powered from mechanical vibration that naturally occurs in the environment. Haven’t heard much about it lately. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 1, 2023, 11:56pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/26 "2023-06-01T23:56:56Z")
Try 10 square meters for one watt. 10 square kilometers would generate 1 megawatt. Still not high power density, that’s for sure. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 2, 2023, 12:02am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/27 "2023-06-02T00:02:02Z")
I get the feeling many of these types of researchers measure a voltage somewhere and proclaim “Eureka! Free energy!” Not realizing, of course, that voltage isn’t power. Voltage is easy to produce, and is often free. Power, especially high exergy power, is not so easy to produce, and is never free. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [June 2, 2023, 12:23am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/28 "2023-06-02T00:23:46Z")
> [@LSLGuy](#): > > Try 10 square meters for one watt. 10 square kilometers would generate 1 megawatt. Still not quite right. 1 µW per cm2 = 1 W per 100 m2. That’s 10 meters squared, not 10 square meters. And 10 square kilometers would generate 100 kW. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [June 2, 2023, 1:26am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/29 "2023-06-02T01:26:52Z")
Note any actual device would be stacked; it’s not like a solar panel. ---
**Author:** ![PhillyGuy](https://avatars.discourse-cdn.com/v4/letter/p/ed655f/32.png) [@PhillyGuy](https://boards.straightdope.com/u/PhillyGuy)\ **Post date:** [June 2, 2023, 1:45am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/30 "2023-06-02T01:45:41Z")
> [@Crafter\_Man](#): > > I get the feeling many of these types of researchers measure a voltage somewhere and proclaim “Eureka! Free energy!” Not realizing, of course, that voltage isn’t power. Are there really many of these types of researchers? The lead scientist is from the Department of Electrical and Computer Engineering at the University of Massachusetts, Amherst. MIT, no. The UMass department seems to be ranked 55 in the U.S. That’s good enough that I don’t think there are a lot of researchers, of that type, making dumb public mistakes about voltage vs. power. I’m no scientist, but I read history of science. It seems to me that the way these things work is that a genuine scientist finds some effect that is incredibly tiny. Then they, and others, try many ways to ramp up that tiny effect into something useful. Usually they fail. And sometimes they succeed. Is it probable that a century from now, the Univerisity of Massachusetts will be known a the birthplace of low-cost safe climate-positive energy production? Right now, with what I know – probably not. But some press coverage, even if the probability for permanent success is a bit low, is reasonable. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 2, 2023, 2:18am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/31 "2023-06-02T02:18:47Z")
> [@markn\_1](#): > > > [@LSLGuy](#): > > > > Try 10 square meters for one watt. 10 square kilometers would generate 1 megawatt. > > Still not quite right. 1 µW per cm2 = 1 W per 100 m2. That’s 10 meters squared, not 10 square meters. And 10 square kilometers would generate 100 kW. Thanks. I came up with your answer first, then changed it. All in my head, no paper or notes. D’oh! ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [June 2, 2023, 2:42pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/32 "2023-06-02T14:42:58Z")
> [@PhillyGuy](#): > > Are there really many of these types of researchers? No. Getting that feeling is a symptom of reading the university press office regurge instead of the actual paper. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 2, 2023, 3:40pm UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/33 "2023-06-02T15:40:29Z")
Yes, that’s another good point: not everything can be “scaled up.” ---
**Author:** ![peccavi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peccavi/32/388_2.png) [@peccavi](https://boards.straightdope.com/u/peccavi)\ **Post date:** [June 4, 2023, 4:45am UTC](https://boards.straightdope.com/t/free-electricity-from-air/984556/34 "2023-06-04T04:45:20Z")
> [@Ruken](#): > > Note any actual device would be stacked; it’s not like a solar panel. Well… > **[Multi-junction solar cell](https://en.wikipedia.org/wiki/Multi-junction_solar_cell)** > > Multi-junction (MJ) solar cells are solar cells with multiple p–n junctions made of different semiconductor materials. Each material's p-n junction will produce electric current in response to different wavelengths of light. The use of multiple semiconducting materials allows the absorbance of a broader range of wavelengths, improving the cell's sunlight to electrical energy conversion efficiency. > Traditional single-junction cells have a maximum theoretical efficiency of 33.16%. Theoretically, a... [Previous page](https://boards.straightdope.com/t/free-electricity-from-air/984556.md?page=1)