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Steam Networks

worksinprogress.co

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Re: Steam Networks

#81

Post by nine_k »

imglorp wrote: post #30

The article cites end-to-end efficiency as 60%. Plus the costs of maintaining steam generators and the pipe network. Electrical transmission systems are roughly 85% efficient to the consumer; together with boring old resistive electric radiators which are 100% efficient. So is there any reason to subscribe to the steam system for new construction?

In most places with district heating, the heat that goes to the heating system is waste heat which turbines of a nearby power plant cannot use. This applies to fuel-fired and nuclear power plants alike. (Keywords: Carnot cycle efficiency.)

So using electricity for heating would be just throwing free heat away. Heat distribution networks are of course not free though.

Electric heating would be an economical win if the electricity could be harvested by solar and wind generators, and stored. Storing solar heat directly is much trickier.

Re: Steam Networks

#82

Post by quickthrowman »

strgrd wrote: post #78

How common are district heating systems? Montpelier in Vermont uses wood stoves to deliver steam to a large part of their small downtown: https://www.montpelier-vt.org/427/Project-Background

I live in Minnesota and both Minneapolis and St Paul have district heating and cooling systems in their downtown core areas. Cordia Energy operates the Mpls network and Evergreen Energy operates the St Paul network. I’m unsure what the fuel source is for the Mpls network but the St Paul network uses wood chips/wood waste and natural gas.

Minneapolis: https://cordiaenergy.com/our-networks/minneapolis/

St Paul: https://www.districtenergy.com/

Re: Steam Networks

#83

Post by whatevaa »

nightpool wrote: post #76
whatevaa wrote: post #66

Earlier quoted context omitted.

So at -20 and below they are basically very, very expensive resistive heaters. Good for medium climates, bad further north. Also either need very expensive oversizing or backup heat sources to compensate reduced heat output, even if you get occasional cold spikes. Unfortunately nothing in life is as simple as it first seems.

How often does it get to -20f in New York City?

Ahh damn, I forgot unit, I meant -20C, so -4F

Re: Steam Networks

#84

Post by xattt »

strgrd wrote: post #78

How common are district heating systems? Montpelier in Vermont uses wood stoves to deliver steam to a large part of their small downtown: https://www.montpelier-vt.org/427/Project-Background

Charlottetown, a city of 38,000, has a waste-to-steam plant that heats the hospital, downtown and the university.

The 30-year-old steam network springs leaks every so often, so you see gurgling hot springs from the ground.

I’d love to know how much cheaper it would be to use this form of heating for my home compared to oil heat.

(1) https://www.enwave.com/locations/pei.htm

Re: Steam Networks

#85

Post by abeppu »

dietr1ch wrote: post #45
proee wrote: post #41

Earlier quoted context omitted.

Except you can ONLY use steam for heating and transporting it over distance is not efficient. If you turn steam into electricity you can use it for ANYTHING and transport it over long distances efficiently.

It also means that at the local scale it might be better to distribute steam. Think about future residential nuclear plants. It might not be worth investing into steam distribution on top of electrical as electrical is more flexible, but there might be steam that's residue otherwise that could be used on heating.

> future residential nuclear plants

What does this mean? Are you imagining a future where individual houses have their own nuclear plants? Or where nuclear plant workers live on-site?

I'm get the argument that we should have more nuclear power, and that some future reactors may be small, but I don't understand the expectation that they would be close enough to residences to pipe steam.

Re: Steam Networks

#86

Post by hwillis »

imglorp wrote: post #30

The article cites end-to-end efficiency as 60%. Plus the costs of maintaining steam generators and the pipe network. Electrical transmission systems are roughly 85% efficient to the consumer; together with boring old resistive electric radiators which are 100% efficient. So is there any reason to subscribe to the steam system for new construction?

> Usage fees are then added on top, paying anywhere from $11.35 per megapound in the summer to $35.013 during peak season.

Steam with For comparison natural gas costs a couple dollars per MMBtu and wholesale electricity costs $40-$60 per MWh. *The steam is orders of magnitude cheaper.*

If the article's quoted prices are accurate (note: Lincoln Towers seems to pay $2.43 per megapound, significantly less than the $11.35 usage fee the article gives immediately before. Not sure what's up.) then steam is practically free. I'm not really sure how that's possible; maybe there are subsidies or regulations enforcing production. A significant amount of the steam is from cogeneration, where steam is a byproduct of pollution-reducing processes- it makes sense that would reduce the cost, almost all steam would need to be a byproduct to explain the price.

Re: Steam Networks

#87

Post by vel0city »

lxgr wrote: post #26
triceratops wrote: post #19

Earlier quoted context omitted.

It would be a shitty steam network that allowed steam to just leak.

Steam rising out of manholes is definitely commonplace in NYC: [1] There's a stretch of sidewalk in the Financial District that gets so hot that you can feel it walking past on some days. And apparently, sometimes these things explode... [2] As far as I've heard it's not (all) actual leaks, though, but rather water dripping on the exterior of the hot pipes carrying the steam itself being evaporated. [1] https://en.wi…

It's often not the steam pipes leaking. The sewers are very humid and warmer than the air above. As the air convects up it hits the cold air and the humidity condenses. The same thing happens in lots of other cities when the weather is right.

Maybe the steam pipes keeps the sewers warmer in places with steam but they should be well insulated in the end.

Re: Steam Networks

#88

Post by glenstein »

imglorp wrote: post #30

The article cites end-to-end efficiency as 60%. Plus the costs of maintaining steam generators and the pipe network. Electrical transmission systems are roughly 85% efficient to the consumer; together with boring old resistive electric radiators which are 100% efficient. So is there any reason to subscribe to the steam system for new construction?

>Electrical transmission systems are roughly 85% efficient to the consumer; together with boring old resistive electric radiators which are 100% efficient.

I'm wary of attempting comparisons of end to end efficiency, just because these aren't apple to apple comparisons. Solar panels are 20% efficient. Nuclear power can be anywhere between 60 and 90% efficient. Coal plants can be between 35 and 50% efficient. Each of these can have an economic rationale despite these differences in efficiency.. A Dyson sphere with 0.001% efficiency could be a winning value proposition. Granted, these are energy sources rather than transmission infrastructure, but the point is the same.

I would want to know about the efficiency loss from whatever primary source of energy was generated before it gets transmitted across the electrical transmission infrastructure, and I would want to know how it compares to a steam source, which could plausibly be such a thing as waste heat. If your steam is cheap or potentially even free it could conceivably win out in the final assessment, even if it has higher relative transmission losses.

Re: Steam Networks

#89

Post by arrosenberg »

Peanuts99 wrote: post #31
coryk135 wrote: post #25

This part really caught my attention: > in 1962, the anthracite seam under Centralia, PA – 25 miles to the west of Lehigh County – caught on fire and is still burning today.) That’s crazy to think that for over 60 years there’s been an underground coal mine on fire. I wonder how long the mines will burn for. The pictures on Google are quite interesting.

There's Burning Mountain in Australia which has been burning for thousands of years.

And a burning crater in Turkmenistan that's been going since the 70s.

Re: Steam Networks

#90

Post by riggsdk »

LeifCarrotson wrote: post #71
imglorp wrote: post #30

The article cites end-to-end efficiency as 60%. Plus the costs of maintaining steam generators and the pipe network. Electrical transmission systems are roughly 85% efficient to the consumer; together with boring old resistive electric radiators which are 100% efficient. So is there any reason to subscribe to the steam system for new construction?

Those electrical systems are about 85% efficient once the chemical energy in the coal has been converted to kinetic energy in the turbine. Losses in the generators themselves and in voltage loss through transformers and wires add up to about 15%. But they're only about 33% (old tech) to 45% (best-case new tech) efficient when it comes to thermal potential. Burning coal or natural gas produces lots of heat, and while…

Random thought: could you insulate high voltage wires in pipes and blow cold air through those? Any loss would become “free” heating for homes nearby.
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