Hygroelectricity
Hygroelectricity is a type of static electricity that forms on water droplets and can be transferred from droplets to small dust particles. The phenomenon is common in the Earth's atmosphere but has also been observed in the steam escaping from boilers (see Armstrong effect). It was the basis for a proposal by Nikola Tesla to tap electricity from the air, an idea which has been recently revived.<ref name="miles">Miles, Ned Carter (2023-07-02). "'It was an accident': the scientists who have turned humid air into renewable power". The Observer. ISSN 0029-7712. Retrieved 2023-07-06.</ref> Hygroelectric charge is the likely source of the electric charge which, under certain conditions such as exist in thunderstorms, volcanic eruptions and some dust storms, gives rise to lightning.<ref>Ducati, Telma R. D.; Simões, Luís H.; Galembeck, Fernando (2010-09-07). "Charge Partitioning at Gas−Solid Interfaces: Humidity Causes Electricity Buildup on Metals". Langmuir. 26 (17): 13763–13766. doi:10.1021/la102494k. ISSN 0743-7463. PMID 20704354.</ref><ref>Gouveia, Rubia F.; Galembeck, Fernando (2009-08-19). "Electrostatic Charging of Hydrophilic Particles Due to Water Adsorption". Journal of the American Chemical Society. 131 (32): 11381–11386. doi:10.1021/ja900704f. ISSN 0002-7863. PMID 19637867.</ref>
As of 2023, a team at the Lisbon-based Catcher Project have generated a 1.5 V 10 mA current using a 4 cm-diameter device.<ref name="miles" />
