Green update for Duluth water infrastructure?

Duluth definitely has some gravity-fed municipal water lines running down the hill. Perhaps as we repair/replace our aging water lines we could make upgrades that will generate electricity.

Portland now generates electricity from turbines installed in city water pipes

6 Comments

sp1

about 7 years ago

Those are really neat. Seems like it would work with the hills in Duluth, too.

Kodiak

about 7 years ago

Whether it's "wah-ter" or water, this floats my boat. Vis-a-vis Duluth, is the application to stormwater mains? Anybody game to advance this to the local authorities? Would that be Duluth Dept of Water & Gas, WLSSD or what?  

An overlooked "industry cluster" that I've never heard talked about is freshwater research and innovation. Like Mayor Ness' push to make Duluth a national center of aviation, Duluth has the makings to be a global center for freshwater. Water is going to supplant oil as the most contested world commodity.  

Duluth has a natural advantage and a head start on the rest of the world as it is the largest seaport on the Great Lakes at the head of the world's largest freshwater lake. It is home to the U.S. EPA Mid-Continent Ecology Laboratory, the Large Lakes Observatory, the Great Lakes Aquarium, NOAA's Minnesota Sea Grant and the DNR Duluth Area Fisheries.

Seems to me that with a bit more applied research and venture capital, Duluth could spawn start-up companies that become the next Lucid Energy (in the video) bringing technological innovation to the local area and then the rest of the world.

cb1037

about 7 years ago

This would not work in Duluth because the water needs to be pumped to the top of the hill first. What you have described is basically a perpetual motion machine, violating a few laws of thermodynamics. You can't get more energy out of a system than you put in.

cb1037

about 7 years ago

I may have misunderstood you though, if you were talking about storm or sanitary sewer rather than fresh water pipes. There is some potential energy that could be recovered from dirty water, but turbines need fairly clean water. People flush things they shouldn't and the city has a crew of people who's job it is to clear condoms and tampons out of lift station pumps. Storm sewers have the same garbage, but also small trees and 2x4's. 

I think this kind of system is only feasible if a city's fresh water source is at an elevation above most of the population.

Kodiak

about 7 years ago

CB1037 - I wish SP1 would respond because I too inferred that she/he meant stormwater sewers because Lake Superior is the source of Duluth's freshwater.  The pumping stations used in Duluth are to pump fresh mains' water uphill from the water works at Lake Superior level.  So, I'm inclined to think it wouldn't work for fresh water in Duluth.  

A little reading up on Portland and I learned that the Bull Run River and its watershed is the source of freshwater there and it is fed by rainfall and snowmelt from the Cascade Range. The metro's freshwater is gravity fed into the main underground reservoir in southeast Portland.  

Unless there is freshwater contraflow in Duluth that I don't know about, it looks like stormwater is the only available option notwithstanding those trees and 2x4s you highlighted. Then again, there are log booms on the Bull Run that block logs and branches so maybe an innovative filtering system could be installed on the main lines where turbines would operate.  ????

cb1037

about 7 years ago

I posted that before I actually read the article. It does say that this would only work for cities that get fresh water from a higher elevation.

There are devices that filter large debris in stormwater, but they need regular maintenance and it would require an engineering study to determine whether the electricity produced would cover those costs. It would need to be done on one of the underground rivers. A power source that only supplied power when it rains would certainly not be cost effective.

The underground rivers mostly run through brick pipe arches, so it wouldn't be as simple as replacing a section of pipe with a turbine. You would basically need to construct an underground hydroelectric plant. My gut feeling as an engineer is that the idea is possible, but not feasible.

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