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Why steam rises from San Francisco streets
- elcomet 4y agoThis article actually never answers the question, why does this steam network releases steam in the streets?
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- randyrand 4y agobad pipes
- wongarsu 4y agoSo what's up with maintenance? The leaks seem trivial to locate and visibly waste both heat and water. How is it more economical to have enough leaks that people start talking about it instead of doing proper maintenance? Especially since this situation seems fairly unique, I've never seen this outside the US, and could only name San Francisco and New York as places where this happens. So what discourages maintenance in those places compared to everywhere else?
- sidewndr46 4y agoAs long as a service provider can pass those costs onto customers and there is no alternative service, it can't be economical to make repairs. You'd be expending capital to decrease revenue.
- wongarsu 4y agoBut everyone is facing roughly the same forces here. You either spend money on maintenance, or you lose money in leaks. It's a tradeoff, but any place outside SF and NYC seems to determine that the best place in that tradeoff produces barely any leaks that a pedestrian would notice.
- Scoundreller 4y agoWater distribution works the same way. Large systems lose like 10% of their supply through leaks in the system but just pump more through the system to make up for the losses. Just like drug smugglers.
- kevincox 4y agoThis doesn't make sense. Price isn't set by the cost of service. You could fix the leaks and still raise the price to increase your profit margin.
- zamnos 4y agoThe energy market in California is highly regulated and the prices consumers pay are fixed by the California Public Utilities Commission (CPUC), and are designed to cover the utility's costs, plus a "reasonable" profit.
- sidewndr46 4y agoIf it was an absolute free market with no barriers to entry sure. I've never lived anywhere that energy, water, or sewer was a free market. My natural gas supplier for example (which is used primarily for heating where I live) routinely raises prices and always flouts state law. My only option would be to discontinue use of natural gas, which would cost me even more money.
- toast0 4y agoSteam leaks is a big indication that you've made it as the downtown of a metropolis. I've witnessed it in Seattle, pretty sure in Chicago and not sure about Milwaukee. Doing proper maintenance requires opening the streets, which is expensive and causes confusion and delay, so there's some amount of acceptable leak before it's a good idea to fix it. There's always a chance of finding unmapped critical infrastructure when you dig, which adds more risk. Plus, when you fix it, you lose the street cred.
- wirrbel 4y agoI live in a town with teleheating, frankly I never saw it steem. I would say the upkeep in the US of the infrastructure is just bad. This reminds me that in Paris you can pretty often see water flowing on the street, it seems that the Paris water supply has a tendency to leak that I just don't see in other towns (but then, i am really walking for kilometers through the city when visiting paris so maybe I just have more opportunities to spot leaks).
- Scoundreller 4y agoParis regularly cleans its streets with the non-potable water supply of its two-stream h2o distribution system. Probably an antiquated practice back from when not everyone had sewer connections and would dump their waste pots on the road, but they still do it. https://parisianfields.com/2012/03/11/a-most-unusual-water-system/ https://parisianfields.com/2012/03/11/a-most-unusual-water-s...
- wirrbel 4y agoInteresting!
- pests 4y agoWitnessed in downtown Detroit too.
- mikeryan 4y agoIs this a guess? I’d think there would be some sort of safety system for venting pressure. Or even condensation around the hot pipes (which seems to be why the same thing happens in New York which also has a steam network) All of the above could work too.
- greysteil 4y agoIf it’s the same as NYC then the steam you see is generally from water evaporating off the outside of the pipes (not steam escaping from the pipes). The pipes are very hot, so any outside water that touches them quickly turns to steam. https://web.archive.org/web/20160811170408/http://www.coned.com/steam/kc_faqs.asp https://web.archive.org/web/20160811170408/http://www.coned....
- jwr 4y agoThat means the whole thing is incredibly wasteful. I always wondered why nobody seems to care about the huge amounts of energy being wasted in NYC in this way.
- tommoor 4y agoIn NYC the steam is from co-generation facilities which produce electricity first, so the steam is essentially waste product to begin with – in most coal plants for example you'd just have giant steam stacks to condense the water again. But yes, it's all very normalized waste.
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- lukeschlather 4y agoThere's an invisible component which is the efficiency of the furnace used to create the heat. Suppose every building uses a small furnace which is 30% efficient, then there's no visible waste heat in the streets. On the other hand, suppose a bunch of buildings use a single furnace which is 50% efficient and pipe the heat with 10% waste from piping. You're still substantially less wasteful to use the central furnace. There's no such thing as a system that doesn't generate waste, and the visibility or invisibility of the waste doesn't tell you how wasteful the system is.
- thaumasiotes 4y agoWhat does it mean for a heating furnace to be less than 100% efficient? Efficiency is normally measured in terms of how much waste heat you generate. If your goal is to produce heat, it isn't possible to produce any waste heat.
- tedunangst 4y agoBecause steam is warmer than the surrounding air, and thus rises. Anyway, https://en.wikipedia.org/wiki/District_heating https://en.wikipedia.org/wiki/District_heating.
- fulafel 4y agoOther parts of the world with district heating don't leak steam. Is it just because they use (liquid) water and not steam? The water is still plenty hot enough for steam to form in leaks, so there's perhaps some factor that makes leaks more tolerable in steam systems? Different corrosion concerns perhaps, air leaking in is less corrosive?
- wongarsu 4y agoOur smallish city has district heating with hot water, and no steam rising from the streets.
- tedunangst 4y agoI think it's an American thing. Our pipes are just that much freer. New York and Philadelphia systems leak steam, too.
- mangecoeur 4y agoSteam based systems are just obsolete, steam under pressure leaks easily unless you do plenty of maintenance. Most district heating systems use liquid water in a closed loop. In fact most operators today are looking to further reduce temperatures to reduce losses and improve efficiency. You only let this much steam escape if you really dont care about saving energy/money
- bobthepanda 4y agoThe issue is generally for these large historic systems, the capital cost of replacement is larger than the savings. Because the streets of New York had many utilities laid out very early, there’s poor mapping and everything underground is haphazard, and disrupting somebody else’s utility system will get them to sue you.
- ElfinTrousers 4y agotl;dr: leaky steam pipes in district heating in downtown SF. Same reason you get it in NYC.
- mokarma 4y agoYup, we have it in Detroit too. https://www.hourdetroit.com/community/whats-the-source-of-the-steam-pouring-out-of-detroits-sidewalks/ https://www.hourdetroit.com/community/whats-the-source-of-th...
- ElfinTrousers 4y agoNot only is district heating energy-efficient, it's great for setting a real film noir atmosphere.
- grogenaut 4y agoOne time walking past union square I saw smoke and flames coming out of the cable car slot. There was just a cop watching it and waving people around. Pretty sure just waiting on the repair crew. Totes normal.
- nharada 4y agoMeanwhile over in Chicago this is called "working as expected": https://www.cnn.com/2019/01/30/us/chicago-train-tracks-fire-trnd/index.html https://www.cnn.com/2019/01/30/us/chicago-train-tracks-fire-...
- bfrog 4y agoChicago experiences -30 to 110 F approximately across seasons at the extreme end. It can be both very cold and very hot here.
- babyshake 4y agoIt's tempting to make a joke about how in that neighborhood, you're lucky if the worst thing you see is flames coming out of the ground.
- wolfgang42 4y agoThis post is basically a less-detailed blogspam of Cordia’s marketing page: https://cordiaenergy.com/our-networks/san-francisco/ https://cordiaenergy.com/our-networks/san-francisco/
- barbazoo 4y agoThanks Google for making the internet shitty!
- willcipriano 4y ago> plants produce steam and pipe it to approximately 180 customers for space heating, domestic hot water, air conditioning Had no idea you could make a steam powered air conditioner. https://en.m.wikipedia.org/wiki/Steam_jet_cooling https://en.m.wikipedia.org/wiki/Steam_jet_cooling
- sbierwagen 4y agoYou can run a refrigerator off of any heat source: burning propane, solar heat, etc https://en.wikipedia.org/wiki/Absorption_refrigerator https://en.wikipedia.org/wiki/Absorption_refrigerator
- ginko 4y ago>Critics of the system point out that the system produces heat, but also wastes nearly 250,000 gallons of water per day, according to a 2015 story by CBS Bay Area. Any reason why they couldn't use ocean water?
- throwaway173738 4y agoSalt water ruins everything it comes in contact with.
- Scoundreller 4y agoAs someone that maintains two vehicles located in the rust belt/salt belt, I concur.
- PeterisP 4y agoSaltwater corrodes all the metal parts, and you simply can't use it for a steam cycle as the salt would pile up as the water turns to steam.
- donalhunt 4y agoGoogle's datacenter in Hamina, Finland uses salt water for one of the cooling loops. aiui it was not trivial to incorporate the salt water loop (corrosion was an issue) but they've made it work. https://www.wired.com/2012/08/google-finland-data-center/ https://www.wired.com/2012/08/google-finland-data-center/
- jldugger 4y agoGoogle also has a 30 percent profit margin, even after accounting for boondoggles like that.
- mikeryan 4y agoBuilding a system from the ground up to use saltwater is a whole different ballgame then trying to retrofit an existing legacy network though. It would probably be cheaper to just convert to another heat source all together.
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- bloomingeek 4y agoI'm about to retire from this very trade, so here's my 2 cents. In my city the boilers run at 600psi.(Not near any salt water, however if we decided to use it if we could, removing all the impurities from the feed-water would be to expensive. At our psi the feed-water must be clean and deaerated to protect the boiler tubes.) I'm a plant operator so I don't fix leaks in the field, these steam leaks are just that, small leaks that develop in the steam supply piping or the condensate return piping. (True, some lines aren't insulated properly in the maintenance boxes, so you do get some pulverized condensate.) The steam generated from the main plant is used for all kinds of applications. Heating of course, whether live steam or heating water using a heat exchanger. Also it is used to power steam turbine chillers to create chill water, which cools a significant amount of office buildings and manufacturing plants. (These chillers use refrigerant, usually 134a, to cool down the water being pumped through them, which is then pumped to where the cooling process is needed. Sometimes these pumps are steam driven, but are usually electric motor driven. Water temp leaving the chiller is usually 38 degrees, but may be around 42 by the time it arrives to where it is used.) My plant uses natural gas to create steam. Many electrical generating power plants still use coal or nature gas to heat treated water to create the steam to spin the turbines which spin generators to create the electricity. (Sorry, I’m not a very good writer.) There are many other applications for steam boilers, and no matter what they are, there’s always the threat of leaks. The cleaner the system, whether steam of water, the better the chances of not corroding the piping. This is done by using chemical treatments to destroy the oxygen or rust inhibiters.
- schoen 4y ago> This is done by using chemical treatments to destroy the oxygen I couldn't help thinking of the fictional weapon used against Godzilla: https://godzilla.fandom.com/wiki/Oxygen_Destroyer https://godzilla.fandom.com/wiki/Oxygen_Destroyer
- arbuge 4y agoIn NYC also: https://www.bloomberg.com/news/articles/2015-10-23/why-steam-rises-from-the-new-york-city-pavement https://www.bloomberg.com/news/articles/2015-10-23/why-steam...
- deepsun 4y agoWould be way more efficient if that was an power plant (electricity generation), that just made use of its waste heat. There were plenty of those in USSR, but I guess not everyone likes a power plant in the neighborhood.
- cbovis 4y agoSeeing steam rise from the streets in NYC blew my mind. I'd always assumed it was just done for dramatic effect in the movies.
- ben_bai 4y agoAnswer: Old one way heating infrastructure where the steam gets generated, distributed, used, and then the condensed hot(warm) water gets dumped into the sewer. This can also just dump steam directly into the sewer. Get a real steam guy to repair and optimize your steam heating system!