Comments on: Delhi Students To Generate Power From Wind Produced By Metro Rail

By: sunny

sunny — Wed, 24 Sep 2014 19:32:00 +0000

Nowdays light weight windmills are coming which can work in less windy places too.

By: SARTHAK ACHARYA

SARTHAK ACHARYA — Fri, 20 Jun 2014 05:08:00 +0000

but the train will violate the laws of nature the resistance offered by it will surely reduce the speed of train

By: kvkell

kvkell — Wed, 18 Sep 2013 10:48:00 +0000

Has anyone found any more information on this project? I can’t find much at all on the members of the team, the professors involved, the station they installed it at, or the results of their work. The original article at Hindustan Times very unscientific and I don’t trust it’s reliability.

By: Zachary Shahan

Zachary Shahan — Fri, 01 Mar 2013 18:52:00 +0000

Yeah, I wondered the same. And I figure that what you postulate is the case 99% of the time.

Footnote would be a fine option. I will use the actual quote so it’s one us less and add the footnote.

By: Hans

Hans — Fri, 01 Mar 2013 12:50:00 +0000

I wonder if the error is by the students, or by some press officer who “corrected” the units. I suspect that a lot of people are confused by the fact that Wh means Watt times hour, because they are used to units like miles per hour. When they than see Watthour they think: that must be a mistake let me correct that.

By the way, why not a little footnote with Bill Woods’ comment? Having no numbers makes the article a bit bland.

By: Zachary Shahan

Zachary Shahan — Fri, 01 Mar 2013 10:39:00 +0000

unfortunately, those figures are from a direct quote from the source. so i’ve simply removed them. i’d assume they should be what Bill writes, but not going to leave them in based on an assumption.

By: Hans

Hans — Fri, 01 Mar 2013 08:55:00 +0000

That is rather obvious, I was just trying to educate. I find it frustrating that even at a site specialised in technology they cannot get their basic units right.

By: Bill_Woods

Bill_Woods — Thu, 28 Feb 2013 20:47:00 +0000

Presumably those should be
‘… 500 watts [or 500 watt-hours per hour] (or 12 kW-h in a day). …
200 watts (or 4.8 kW-h in a day), …’

By: Hans

Hans — Thu, 28 Feb 2013 15:11:00 +0000

also see:

http://cleantechnica.com/2013/02/27/hands-on-learning-with-bike-powered-generators-can-you-explain-what-a-watt-is/

By: Hans

Hans — Thu, 28 Feb 2013 12:40:00 +0000

“200 watts per hour (or 4.8 kW in a day)” does not make much sense

Let me shed some light:

Joule is the SI* unit for energy.

Power is the energy converted** per time. Its unit is therefore Joule per second (J/s)

Watt (W) is just another name for Joule per second: 1W=1J/s.

Now comes the confusing part: in the electricity world they use Watthours as unit for energy. This is the energy converted in an hour when the power is 1 Watt.

1 Watthour= 3600 Wattseconds = 3600 (J/s)*s=3600 Joule.

Watt per hour only makes sense when speaking of an increase of power.

Now you know it, spread the word to other energy bloggers.

*System internationale

**Energy is never produced, it is just converted from one form to another form.

By: Mridul Chadha

Mridul Chadha — Thu, 28 Feb 2013 04:30:00 +0000

I don’t much idea about the technicalities but yes, the trains stop every 1-1.5 kms so they have to slowdown frequently. Plus, I believe the speeds differ when the trains are running on elevated tracks and underground tracks.

The DMRC has allowed the students to install a system at one of the underground stations. I’ll try to find out which station it is and have a closer look at the system, if they allow me to.

By: Zachary Shahan

Zachary Shahan — Thu, 28 Feb 2013 00:27:00 +0000

The only thing I was thinking was if they were installed somewhere far enough out of the trains path and simply receiving some wind overflow somewhere that wouldn’t affect the train’s wind tunnel. But, doesn’t really sound like that’s the case, and don’t think placement in such a location would be of any use anyway. And for all I know, it’d still interfere with the train’s wind tunnel.

By: Otis11

Otis11 — Thu, 28 Feb 2013 00:18:00 +0000

Doubtful – I don’t see how they could bend the Physics… Unless you want the train to slow down at those points???

By: Zachary Shahan

Zachary Shahan — Wed, 27 Feb 2013 23:56:00 +0000

That’s the same thing that crossed my mind reading this, but was afraid I might be missing something.

By: Otis11

Otis11 — Wed, 27 Feb 2013 23:51:00 +0000

As described, this will not work. The students are overlooking a fundamental physical principle – you can’t get energy from nothing! The energy that they are harvesting from the “wind” generated by a train going by will disrupt the wind-tunnel that the train has created, disrupting the laminar flow right around the train and increasing drag on the train.

This system will effectively pull energy from the train, but at the expense of the trains efficiency.

Good job thinking outside of the box, but this one doesn’t quite work.