Elecrical Energy from Raindrops?: Physics Help Needed

RFACE | 6.26.08 | rface

[rface]

How much electrical energy could be converted from this rain energy?.......

So I look out the window and I see all kinds of energy being wasted. Each little raindrop splatting on the ground is a potential source of perfect green energy. Why hasn’t some enterprising nerd figured this out?

Perhaps somebody here could do some calculations:

Here’s some assumptions I might make…….

1) Each raindrop weighs 0.1 grams

2) Raindrops have a terminal velocity of 5 meters a second.

3) Let’s say that 1 sq. meter is hit by raindrops 100 times a second for an hour.

These are assumptions that I just guess at from a quick observation – so they might not be very accurate.

QUESTION: How much electrical energy could be converted from this rain energy?

(kinetic energy => electrical energy)

[chimera]

Your example is a good one for the problems of dealing with a very diffuse energy source. Fundamentally, you are correct, each raindrop has kinetic energy. But gathering that in sufficient quantities to convert to useful work is a challenge. You have to devise very large systems to capture economical quantities of useful energy from an inherently diffuse source, and even if you could the cost might exceed whatever you could make from generating energy that way. That's why you need windfarms covering hundreds of square miles of territory to equal the output of a nuclear plant. One is a diffuse source, the other very intense.

[jpsb]

E=MV**2 or in englist e equalts mass times velocity squared

so E=.1g X (5meters/sec) **2 e= .25gm/sec squared for each rain drop. .25 gram/meters squared does not sound like alot of energy to me.

[grjr21]

So I look out the window and I see all kinds of energy being wasted

 

Yep ... me too 

 Victoria's Circuit Harnessing the untapped power of breast motion

[jpsb]

Opps forget the 1/2
E = 1/2MV**2

so make the .125 gm/sec**2 (Prety sure gm/sec **2 converts nicely to Joules)

[Gator113]

LMAO..

You could be cooking with gas.....

[Gator113]

I would like your idea to work. I live in western Washington state...We invented rain.

[Rudder]

...tomorrow, I'm going off the grid! :)

Thanks to burritos, refritos and "intestinal fortitude," you've become a real life dynamo!

[skeeterman]

What if some one could build a machine that would suck the oil from the earth and heat it to make steam to power a turbine? WOW that would be great.