Trompe.....

[peaceful_life]

'Bill Mollison explains what a trompe is and how compressed air can provide limitless amounts of clean energy using technology we have had for hundreds of years'

http://www.youtube.com/watch?v=-9NqqDL6bkk


Bill does ramble with the figures from time to time, but...the principal is sound enough.
The Trompe is well enough known in permaculture circles, I question why I've read nothing about it on forums such as this, or indeed heard 'Green' folk tout it's potential?

Anyway...the video is good for the craic of Bills style if nothing else.

[biffvernon]

Genius! I'd never heard of that. Are there any working example?

Ah - http://en.wikipedia.org/wiki/Trompe

That really is an excellent lecture.

And we've all be conned into thinking we need oil!

[peaceful_life]

Genius! I'd never heard of that. Are there any working example?

Ah - http://en.wikipedia.org/wiki/Trompe

That really is an excellent lecture.

And we've all be conned into thinking we need oil!

I've heard of a few, one in Brazil at a large permaculture site, no data yet, but working fine, as far as I know.

Here's a small-scale working model from the Ummm U.S dept of interior. Same principal....
http://www.youtube.com/watch?v=I85esMMoRa4

There is also a hybrid design.

[biffvernon]

Nice video. Well done the Office of Surface Mining.

There really must be loads of applications for this low-carbon technology.

[vtsnowedin]

'Bill Mollison explains what a trompe is and how compressed air can provide limitless amounts of clean energy using technology we have had for hundreds of years'

http://www.youtube.com/watch?v=-9NqqDL6bkk


Bill does ramble with the figures from time to time, but...the principal is sound enough.
The Trompe is well enough known in permaculture circles, I question why I've read nothing about it on forums such as this, or indeed heard 'Green' folk tout it's potential?

Anyway...the video is good for the craic of Bills style if nothing else.

Well it is a workable device but it's potential is most certainly not "unlimited" You are limited to the volume of water you have available and the height from which you can let it fall. The same amount of water falling the same distance through a hydro turbine generator is certainly more efficient and the resulting electricity more readily utilized.

[biffvernon]

Well it is a workable device but it's potential is most certainly not "unlimited" You are limited to the volume of water you have available and the height from which you can let it fall. The same amount of water falling the same distance through a hydro turbine generator is certainly more efficient and the resulting electricity more readily utilized.

Ah but there's a difference. With the trompe the water does have to fall a long way - but then it can be allowed to rise up to very nearly it's original height so the overall loss of head (gravitational potential) is very small. You just need to dig a deep hole to but the equipment in. It can thus be deployed on a gently sloping river with far less head than is needed for conventional hydro-electric generation.

[Catweazle]

Well it is a workable device but it's potential is most certainly not "unlimited" You are limited to the volume of water you have available and the height from which you can let it fall. The same amount of water falling the same distance through a hydro turbine generator is certainly more efficient and the resulting electricity more readily utilized.

Ah but there's a difference. With the trompe the water does have to fall a long way - but then it can be allowed to rise up to very nearly it's original height so the overall loss of head (gravitational potential) is very small. You just need to dig a deep hole to but the equipment in. It can thus be deployed on a gently sloping river with far less head than is needed for conventional hydro-electric generation.

If the water going down holds bubbles of air it will be less dense than the water coming up, so the difference in head between the "in" and "out" will be proportional to the amount of air added to the water.

[vtsnowedin]

Well it is a workable device but it's potential is most certainly not "unlimited" You are limited to the volume of water you have available and the height from which you can let it fall. The same amount of water falling the same distance through a hydro turbine generator is certainly more efficient and the resulting electricity more readily utilized.

Ah but there's a difference. With the trompe the water does have to fall a long way - but then it can be allowed to rise up to very nearly it's original height so the overall loss of head (gravitational potential) is very small. You just need to dig a deep hole to but the equipment in. It can thus be deployed on a gently sloping river with far less head than is needed for conventional hydro-electric generation.

I'd like to see your schematic drawing of how you get any water back above the outlet elevation without adding or using energy to lift it.

[peaceful_life]

Well it is a workable device but it's potential is most certainly not "unlimited" You are limited to the volume of water you have available and the height from which you can let it fall. The same amount of water falling the same distance through a hydro turbine generator is certainly more efficient and the resulting electricity more readily utilized.

Ah but there's a difference. With the trompe the water does have to fall a long way - but then it can be allowed to rise up to very nearly it's original height so the overall loss of head (gravitational potential) is very small. You just need to dig a deep hole to but the equipment in. It can thus be deployed on a gently sloping river with far less head than is needed for conventional hydro-electric generation.

If the water going down holds bubbles of air it will be less dense than the water coming up, so the difference in head between the "in" and "out" will be proportional to the amount of air added to the water.

Wouldn't the ratio of 'in' to 'out' also be dictated by diameter as well as depth'height of the bore shaft and the volume of the release chamber?

Gradient of fall can be compensated with a series of 'locks', maybe even a system of sluiced tidal pools in coastal areas.

[peaceful_life]

'Bill Mollison explains what a trompe is and how compressed air can provide limitless amounts of clean energy using technology we have had for hundreds of years'

http://www.youtube.com/watch?v=-9NqqDL6bkk


Bill does ramble with the figures from time to time, but...the principal is sound enough.
The Trompe is well enough known in permaculture circles, I question why I've read nothing about it on forums such as this, or indeed heard 'Green' folk tout it's potential?

Anyway...the video is good for the craic of Bills style if nothing else.

Well it is a workable device but it's potential is most certainly not "unlimited" You are limited to the volume of water you have available and the height from which you can let it fall. The same amount of water falling the same distance through a hydro turbine generator is certainly more efficient and the resulting electricity more readily utilized.

Of course it's more efficient, it can be utilised for energy in it's gaseous state and also send it through another level of entropy for electricity if desired, but the design itself has virtually no moving parts and extremely low maintenance with great longevity.

[vtsnowedin]

Of course it's more efficient, .

There is no "of course" about it. You have to do the math. Pounds of water times the height in feet dropped from gives the potential energy of the water at the top then the rate it can fall through the pipe gives either the horse power or kilowatt hours potential energy input into the device. With a turbine on the bottom you could just meter the electricity produced. With the compressed air you would have to go to some more equations or actually do some work with it to get a horse power output figure. The fact that it is durable or has few moving parts does not increase efficiency when running just it's lifetime total costs.
Modern water turbines run at efficiency of about 90 percent.
The fact that the big trompe in Canada sits idle beside a water turbine that is more useful tells you the story.

[Catweazle]

Ah but there's a difference. With the trompe the water does have to fall a long way - but then it can be allowed to rise up to very nearly it's original height so the overall loss of head (gravitational potential) is very small. You just need to dig a deep hole to but the equipment in. It can thus be deployed on a gently sloping river with far less head than is needed for conventional hydro-electric generation.

If the water going down holds bubbles of air it will be less dense than the water coming up, so the difference in head between the "in" and "out" will be proportional to the amount of air added to the water.

Wouldn't the ratio of 'in' to 'out' also be dictated by diameter as well as depth'height of the bore shaft and the volume of the release chamber?

Gradient of fall can be compensated with a series of 'locks', maybe even a system of sluiced tidal pools in coastal areas.

No, I don't think so.

Water on the way down, containing air bubbles, is less dense than the water coming back up. You can't fool gravity.

[peaceful_life]

If the water going down holds bubbles of air it will be less dense than the water coming up, so the difference in head between the "in" and "out" will be proportional to the amount of air added to the water.

Wouldn't the ratio of 'in' to 'out' also be dictated by diameter as well as depth'height of the bore shaft and the volume of the release chamber?

Gradient of fall can be compensated with a series of 'locks', maybe even a system of sluiced tidal pools in coastal areas.

No, I don't think so.

Water on the way down, containing air bubbles, is less dense than the water coming back up. You can't fool gravity.

Just means the ratios need engineered into the systems design, the principal is still sound and efficient, especially over the long-term.

[peaceful_life]

Of course it's more efficient, .

There is no "of course" about it. You have to do the math. Pounds of water times the height in feet dropped from gives the potential energy of the water at the top then the rate it can fall through the pipe gives either the horse power or kilowatt hours potential energy input into the device. With a turbine on the bottom you could just meter the electricity produced. With the compressed air you would have to go to some more equations or actually do some work with it to get a horse power output figure. The fact that it is durable or has few moving parts does not increase efficiency when running just it's lifetime total costs.
Modern water turbines run at efficiency of about 90 percent.
The fact that the big trompe in Canada sits idle beside a water turbine that is more useful tells you the story.

The energy is in the amount of air that can be compressed, not volume and velocity of water alone. I guess it'd be not much of an issue to pull off some kinetic energy with a turbine as well, which is another string to the bow of this things diversity.

"The fact that it is durable or has few moving parts does not increase efficiency when running just it's lifetime total costs."......I don't think you're viewing things through the wider EROEI lens and slightly confusing the point of gas apples for electric oranges.

Are you suggesting Ragged Chutes plant sits idle simply because of efficiency?......It's worth noting that as the baseload hydrocarbon supply chain of parts and consumables for the turbine contracts/ breaks down, just which of the two systems are more dependable, tortoise and hare, innit....and keep that EROEI in mind.

[vtsnowedin]

The energy is in the amount of air that can be compressed, not volume and velocity of water alone. I guess it'd be not much of an issue to pull off some kinetic energy with a turbine as well, which is another string to the bow of this things diversity.

"The fact that it is durable or has few moving parts does not increase efficiency when running just it's lifetime total costs."......I don't think you're viewing things through the wider EROEI lens and slightly confusing the point of gas apples for electric oranges.

Are you suggesting Ragged Chutes plant sits idle simply because of efficiency?......It's worth noting that as the baseload hydrocarbon supply chain of parts and consumables for the turbine contracts/ breaks down, just which of the two systems are more dependable, tortoise and hare, innit....and keep that EROEI in mind.

I am quite aware of the EROEI involved here and the hydro turbine producing electricity wins over the trompe by a factor of ten to one. The energy contained in the compressed air produced by the trompe is only about five percent of what was contained in the water at the top of the stand pipe. If you have enough water available and work to do at the site for compressed air you can get that work done but running the same amount of water through a hydro turbine is a much higher EROEI even when including the higher energy investment in building the turbine. Modern hydro turbines with pressurized floating bearings last for decades so the simplicity and durability of the trompe does not swing the equation far in that direction.
The trompe was state of the art in it's day but it has been made obsolete by modern hydro-electric technology. Nobody today with a viable hydro-electric site would build a trompe with his own money.