Substations and Power Lines

[exiled_antipodean]

There's a steel-framed building going up by the Greenway just as it goes over (or across!) Hiawatha. No obvious banner announcing what it is. Does anyone know?

[gobezlij]

It is an Xcel electric substation. See what it will look like here...

http://www.xcelenergy.com/staticfiles/x ... ission.pdf

[Uptown46]

I'm fairly certain what you're seeing is actually Xcel's Hiawatha Substation construction. Here is a link to Xcel's page on the project: http://www.xcelenergy.com/hiawathaproject

Also the Midtown Greenway Coalition has been following the issue of mitigating the visual impacts of the facility and has info here: http://midtowngreenway.org/news-and-dev ... esolution/

I guess the substation is supposed to glow yellow at night. Could be an interesting visual addition next to the blue/purple glow of the Sabo bridge lighting.

[exiled_antipodean]

Thanks for the quick replies!

[martykoessel]

Does anyone know if the construction of the new substation at the Greenway means that the older substation at about 40th and Hiawatha will be dismantled?

[Silophant]

It won't be. The Hiawatha substation is being built to relieve overloading at the Southtown substation, but it will do so by taking over some of Southtown's feeders, allowing both to have room to cover the future power demands of south Minneapolis.

[Gman12]

This new sub will be feeding another new sub at Oakland and the greenway via underground transmission to meet future demand.

[Silophant]

Here's Xcel's page on the projects.

[seanrichardryan]

So, this was clumsily changing colors tonight... Sort of aurora style. I personally like the steady gold lighting.

[Silophant]

Oh, yeah, that got activated recently. I was going to post about it, but couldn't find this thread. The Midtown substation at Oakland and the Greenway has similar lighting.

[TommyT]

Drove by the midtown one not too long ago and it seemed like some of the lights needed to be placed a bit better, Red looked really nice but other colors were lost.

[David Greene]

"Xcel Substation at Sabo bridge"

At first glance I thought this was a new residential project.

[mullen]

haha... so true.

[twincitizen]

Apologies if this was posted earlier: Electricity demand sparks investment in Uptown grid

[RailBaronYarr]

Unless there's something more to it (and maybe Silophant can weigh in?..), this talks a lot about all the new apartments in the area, but then it says the area of focus for the $100k investment is west of Henepin from Lake to 32nd. That area hasn't seen nearly the investment and new load as north of the Greenway, east of Hennepin.

[David Greene]

I've always been amused about how old some of the poles around here are. There's probably not much if any original equipment left but some of the poles have got to be over a century old.

[Silophant]

Disclaimer: I'm not a distribution engineer, so the following is mostly educated guesses. I am not a spokesperson for Xcel Energy.

Basically, electrical infrastructure doesn't really get replaced as long as it's working and not in the way of anything. As David has noticed, wooden poles can last a long long time if they don't start to rot, and copper conductor lasts forever.

The distribution grid in South Minneapolis (and St. Paul, and the older suburbs like SLP) was originally built out in the 1920s or thereabouts. The feeders running to every house were operated at 4160 volts, and were fed from the old substations like Garfield* (33rd and Garfield) and Nicollet (47th and Nicollet), which were themselves fed by 13,800 volt lines coming from places like Main Street and Aldrich substations. Starting in the 1960s, higher voltage transformers got cheaper and all the local feeders started to get converted to run at 13,800 volts, and the small 4kV substations were retired.** The conversion process just involved replacing all the 4,160-240V transformers on a given line with 13,800-240V units, and just like that, you could push 3x as much power through the same conductors, which solved the capacity issues for a long time.

So, the improvements wind up being focused in the SFH neighborhoods south of Lake because that's where you have houses that haven't really changed in decades, and thus haven't forced rerouting and rebuilding of the feeder lines, so they're finally hitting their capacity limits at 13,800V. Where stuff has been redeveloped, like the apartments along the Greenway, they've buried or at least rerouted the feeders as well, which triggered a rebuilding to modern, higher-capacity standards.

*The Amp House, if that's still happening.
**This conversion was finally finished*** in the metro area this year(!), when the St. Clair substation in St. Paul was finally retired. If it ain't broke...
***The knoll and mall areas of the University campus are still operated at 4kV, but that's the University's problem, not Xcel's.

[mister.shoes]

That was far more interesting and insightful and curiosity-provoking than I expected when I started reading. Thanks!

One question, though: how do all those historical numbers compare to "modern, higher-capacity standards"?

[David Greene]

I've learned from my bother-in-law that there is a while subculture around electrical infrastructure. He's really into collecting insulators (has well over 5,000 I'm sure) has numerous pictures of poles, journals full of documentation about his observation of the 4kV conversion in Baltimore, etc. He's always scanning abandoned railroad corridors for old poles and insulators, asking old house owners for the unused insulators on the side of their house, and on and on. It's more than a little Aspergery (in his case). There are literally whole national conventions about this stuff.

Sent from my Nexus 5X using Tapatalk

[mattaudio]

I briefly looked at trying to buy the 47th and Nicollet substation, but environmental headaches would be too much for a conversion. I've seen the headaches Aaron has dealt with on Garfield. I'd develop it if it was a cleared site, but from what I've heard Xcel would need to spend more money on site remediation than I could afford for a finished parcel.

There's also the old brick substation on 32nd and Hiawatha, right up against the Hiawatha sidewalk.

Old phone switching infrastructure is fascinating as well... Over time, these local offices could largely go away as well. Of course for people who still have POTS service, the twisted pair still needs to terminate somewhere. But these are moving towards terminating at utility boxes in boulevards with fiber connectivity in order to allow faster DSL speeds. The switching equipment is so small and efficient, and large telco space is not needed these days.