Please log in.
Before you can vote, you need to register. Please log in or create an account.
Science: Energy: Water: Wave
Bobbing Energy   (+5, -2)  [vote for, against]
Reuse plastic bottles to power generators

Divert plastic bottles out of landfills and recycling streams (with caps intact) and use them for buoyancy, collected in large nets, to power generators through wave action.

Essentially use these large "buoys", attached by cables, to drive a crank on a submerged generator along tracts of otherwise barren coastlines (i.e. North Labrador coast, most of Iceland, and the North Sea).
-- whiprsnapr, Jan 21 2002

The notion of using tidal energy by tapping the motion of anchored floating barges with piezoelectric material is baked, and I can't see the advantage of using bottles.

Maybe you can fill me in.
-- seal, Jan 21 2002


I thought this was about something else altogether.
-- thumbwax, Jan 21 2002


hey whiprsnapr, i told you they wouldn't go for this idea.
-- mihali, Jan 21 2002


Iceland's coastline is barren?
-- bristolz, Jan 21 2002


[seal] The advantage is in the recycling.
-- phoenix, Jan 21 2002


[pheonix] Ahhh. I guess that wouldn't be too unsightly. However, the author did note that he'd take plastic bottles out of recycling streams.

I'm still mulling over whether to give it a fishbone or a croissant.
-- seal, Jan 21 2002


[seal] Remember the saying, "Reduce, Reuse, Recycle"? There's a reason that it's in that order. The most benefit is gained by reducing the amount of raw materials we consume, the next most by reusing things (in such a way that we eliminate the need for something to be manufactured), and the least amount of benefit comes from recycling (due to the energy cost of recycling).
-- mwburden, Jan 21 2002


But thats only if you reuse it for something similar, right? Because otherwise ie. in this case then the two are hard to compare...

Would it take more raw material to build a new float and recycle the bottles or to reuse the bottles as floats and build new bottles?
-- RobertKidney, Jan 21 2002


The problem is that recycled bottles aren't used intact -- they are melted down and made into new bottles. This takes a lot of energy (nearly as much as the cost of material and energy to make the bottle in the first place!)

If you recycle the bottle, then you have 1X for the cost of manufacturing a float and .75X (approximate cost of recycling the bottle). If you reuse the bottle as a float and make a new bottle, then you have only 1X (the cost of making a new bottle). You come out .75X ahead. Even if recycling were much more efficient (.25X) you would STILL come out ahead by reusing the bottle.

If, as you pointed out, it were possible to reuse the bottle as a bottle, they we would probably come out ahead. Unfortunately, that would take a major turnaround in corporate thinking.
-- mwburden, Jan 21 2002


But that assumes that the bottles are just as good at being a float as a custom made float... and you could (maybe) use some of the energy generated to recycle bottles...
-- RobertKidney, Jan 22 2002


I'm no math wiz, but I think it actually assumes that the plastic bottles will be at least 0.5x as efficient at producing energy as a custom-made float.
-- ye_river_xiv, Nov 30 2011



random, halfbakery