generators in a city's water pipes? ayfkm?

[ivymike]

http://realitieswatch.com/portland-just-installed-water-pipes-that-generate-electricity/

Portland Just Installed Water Pipes That Generate Electricity!

Lucid Energy, a Portland-based energy company, has come up with a brilliant idea to harness electricity from the water that flows through a city’s pipes. Small turbines are installed into the pipes which send the energy collected from the flowing water into a power generator.​

I guess all their flow is gravity-driven, then? Or maybe someone else is paying to run the pumps?

 

[KENAT]

All the water doesn't need to be gravity driven, but certainly locally anywhere they put these it it would need to be or they are reinventing the roulette wheel as you imply.

For example, if for some reason they have to pump water over a hill just to get it to it's destination, then on the down-slope maybe recovering the energy makes some sense.

Portions of the California Aquaduct do conceptually similar (on a larger scale), pumping over mounting ranges then scavenging at least some of the PE on the way down.

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[davidbeach]

The bulk of Portland's water system is gravity flow. That installation is "new and sexy" but there are other, much older, locations on the system where pressure reduction occurs in a turbine spinning a generator.

 

[dgallup]

Either they had a lot of excess water pressure that was being wasted in pressure reducing devices at the end user or there are now a lot of end users who are pissed off because they don't have enough water pressure to take a shower.

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[JohnRBaker]

With respect to the California Aqueduct system, most of the movement of the water, from the Sacramento River delta to the greater Los Angeles area (a distance of almost 400 miles), and all the places in between (most of this being used my large commercial agricultural concerns), is the result of gravity feed as the system was carefully routed to take maximum advantage of the topology of the Central Valley of California. Of course, near the end of this journey it is necessary to pump the water up over the San Gabriel Mountains before it actually reaches the people who need it most.

After all, if you look at a map of California you'll see that it's "all downhill anyway"

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
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[davidbeach]

Lots and lots of excess pressure. That Lucid project was in conjunction with a new, huge, reservoir being installed. The reservoir is gravity feed out of the mountains and sits on a butte 300 feet or so above the surrounding neighborhoods.

 

[zdas04]

This is a tiny evolutionary step from the generators installed in a dam. It is actually refreshing to see good engineering making the news.

I looked at a large gas processing plant a few years ago and audited all of the ways that recoverable energy was being "wasted". Just limiting it to "technically recoverable" (e.g., we could replace a choke and a static mixer with an ejector and get rid of a pump while achieving better mixing; we didn't call the heated air out of a heat exchanger as recoverable since the heated air was to dispersed to be an energy source worth harvesting) we calculated that the imported energy could be reduced by 30%. They never did anything with the study, but it was a great academic exercise.

To me the essence of good engineering is avoid being stupid which generally means avoiding the waste of energy unnecessarily.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[GregLocock]

On a related, and possibly obvious note, the town water is delivered up and down hills, from one big main. it is hard to believe that the folks at the bottom of the hill get several additional atmospheres of head compared with those on the top of the hill, so how do the water board equalise the pressure? I'm guessing intermediate holding tanks open to the atmosphere. If so this could replace those

Cheers

Greg Locock


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[BJC]

John Baker
At the end of the California Aquaduct is a 1,120,000 HP pumping station.
There is at least 1 hydro plant on the downhill side.

 

[JohnRBaker]

I've never been up-close to that pumping station, only seen it from a distance as I'm driving on the I-5, nor have I ever seen what the 'other side of the mountain' looks like where I would assume the hydro plane would be located. BTW, I think there's a pumping station about half-way down the Central Valley (not too far from the Harris Ranch) that lifts the water up to a higher level of the aqueduct so as to give it the needed 'head' to make it down to that big pumping station you described, which is at the foot of the San Gabriel Mountains, just a few miles West of the Grapevine.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[cswilson]

This afternoon I will be driving from southern to northern California on I-5, which parallels the California Aqueduct. It's an interesting system, whose design puzzled me for a while.

The thing is, as you drive north in the San Joaquin valley, you are going (slowly) downhill, as the valley drains into San Francisco Bay. Yet the aqueduct is flowing south, that is, "uphill", even to get to the massive pumping station BJC mentions to take the water over the Tehachapi mountains to LA.

So how does this work? The aqueduct runs along the west side of the valley and the hills bordering it. Sections of it actually run "diagonally" out of the hills toward the floor of the valley as the water flows south. Periodically there are pumping stations that pump the water westward up into the hills again for the next free-running section.

It is fun to see if non-engineers can figure out how the aqueduct moves water "uphill". A little amusement for a boring drive, anyway.

 

[cswilson]

As you drive over the Tehachapi mountains on I-5 north of Los Angeles ("The Grapevine") you will see Pyramid Lake near the top, a storage reservoir for the water on its way to LA. Closer to LA, in the Santa Clarita Valley near the Magic Mountain amusement park, you can see the earthen dam for Lake Hughes (but not the lake itself).

Together, these two reservoirs are used as one of the biggest pumped hydro storage systems in the US. Not only do generators at Lake Hughes recover power from the water coming down from the mountains, but at night, water is pumped back up to Pyramid Lake if there is excess generation capacity on the grid.

 

[dgallup]

Sounds like it won't take much of a temblor to disrupt that system and let LA dry up and blow away in the dust.

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[JohnRBaker]

That's why most people in SoCal should be keeping a good supply of bottled water around. At any one time, we have something like a hundred liters or so of bottled water in our garage. I also carry about 10 or 12 liters in the spare tire well of my SUV plus another four liters, one in each door pocket. My wife has maybe six liters in her car. That may not sound like much, but I suspect we have more than the average household has stashed away.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[BJC]

I don't remember the details but at the pumping plant was being built each vendor was to supply a pump for testing. The testing facility was in Scotland. The story was that a fraction of a percent in efficiency would be be very expensive over the life of the project.
LAPWD also proposed a Nuclear power plant in the Southern San Joaquin valley to power the water system.