Harvesting wind energy from flag flapping - Page 1
Forum section: electronics / general

author: Bud
author_rank: Super Contributor
timestamp: July 26, 2022, 03:52:06 pm
content: Capturing the wind's energy using "piezoelectric" flagshttps://physics.aps.org/articles/v8/s12Putting this in Dodgy Technology subforum rather than in Renewable one, since it sounds like it.

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 26, 2022, 04:06:32 pm
content: Interesting, but how many of these would you need to supply a house with enough energy to run whatever appliances?And how long will the material last in these conditions?And are windmills not already invented?Etcetera, etcetera....

author: AndyBeez
author_rank: Frequent Contributor
timestamp: July 26, 2022, 04:57:48 pm
content: From the title I thought this was some clever (crowd fund harvesting) system using the Karman votices spinning downstream of the flag. Seehttps://en.m.wikipedia.org/wiki/Karman_vortex_streetInstead, the flag pole alone is likely to collect many megajoules more energy than a piezzo flag, when providing a ground path for a thunder cloud.

author: helio0centra@gmail.com
author_rank: Contributor
timestamp: July 27, 2022, 08:30:49 am
content: Quote from: pcprogrammer on July 26, 2022, 04:06:32 pmThey'll probably aim lower. Maybe just charge a phone?

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 27, 2022, 08:57:14 am
content: Quote from: helio0centra@gmail.com on July 27, 2022, 08:30:49 amWow that is a great ideaThey can use this in Strasbourg to charge the phones of members of the European parliament

author: PlainName
author_rank: Super Contributor
timestamp: July 29, 2022, 12:48:32 pm
content: Quote from: helio0centra@gmail.com on July 27, 2022, 08:30:49 amIndeed. If it produced any output greater than it takes to collect, surely that's a plus. Not everything has to scale to continent-size consumption.I don't think this is at all dodgy if it works.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 29, 2022, 10:48:03 pm
content: Maybe we could harvest good energy from all the farting.

author: helio0centra@gmail.com
author_rank: Contributor
timestamp: July 29, 2022, 11:17:12 pm
content: It might be a novelty item you see in department stores and TV infomercials in a few years: a flag with USB outputs to charge you phone from the wind. But I can't see it ever being as good as a wind turbine or solar panel.

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 30, 2022, 02:10:34 am
content: Reminds me of an idea someone had to use piezoelectric sheets to generate electricity from flowing water, touting that it's "more environmentally friendly" as it doesn't need a dam. I guess it never occurred to him that it would be far more effective to sit a water wheel in the river, still no dam needed!

author: Bud
author_rank: Super Contributor
timestamp: July 30, 2022, 02:37:35 am
content: There was a research document I've seen elsewhere that claimed getting experimental 3mW of energy out of such gizmo , but special conditions were required such as vibration from the flag matching the resonant frequency of the attached piezo converters.

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 30, 2022, 03:39:21 am
content: Quote from: SiliconWizard on July 29, 2022, 10:48:03 pmYes put micro turbines in our pantsbecause most of us only produce smelly wind instead of usable methane.Another option is to charge our phones when walking, like those self winding watches used to do.But think of cows, it has been looked into way back already. Actually cow dung from big stables is being used to extract methane from.And recently there is also some looking into capturing methane from cow burpsIt is in Dutch but here is a site about it:https://www.agriwijzer.nl/product/39?name=METHAAN+VERMINDERING+OPVANG+KOEIENBOERENEdit: it is not for the actual capture of the methane, it is for health and food efficiency monitoring.

author: PlainName
author_rank: Super Contributor
timestamp: July 30, 2022, 06:49:07 am
content: QuoteSure. But you can't (yet) roll up a solar panel, and they look shit stuck at the top of a flag pole. The thing here is not how much it puts out but that it puts something out where previously there was nothing.Of course, that assumes the product is still basically a flag, and if it churns out half a microwatt no-one is going to use one. But, you know, maybe see what they produce before rubbishing it.

author: tszaboo
author_rank: Super Contributor
timestamp: July 30, 2022, 08:23:13 am
content: I have to link the old SMBC comics again: