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The article cites end-to-end efficiency as 60%. Plus the costs of maintaining steam generators and the pipe network. Electrical transmission systems are roughl

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?

walrus01 2y ago
In terms of thermodynamics, a electric resistive heater is 100% efficient, but if the measurement is how many BTU of heating you can put into a room in a day with a certain amount of watt hours, a modern heat pump will always beat it. Also of course 100% electric.
- graemep 2y ago
  A heat pump is more than 100% efficient on that measure. I am not sure about "always". Does it not depend on the temperature difference? The use cases for steam seem to be where you need more than room heating though: the first paragraph mentions sterilising medical equipment, humidity control, and washing.
  - walrus01 2y ago
    My understanding is that it varies by temperature difference, but there's specialized series of heat pumps which work "okay" with very cold outside temperatures, even down to -25C, which are becoming popular to replace oil tank heating systems in Atlantic Canada. Apparently even when operating at -20C outside air they're still more efficient than electric baseboard heating. I don't know of any of the customers of the steam system in downtown Vancouver that use it for sterilization purposes, it connects almost exclusively large office towers. There's no hospital or medical facilities connected to it.
  - yencabulator 2y ago
    > I am not sure about "always". Does it not depend on the temperature difference? My understanding: A heat pump is always better than resistive electric heating. Sometimes a outside air using heat pump needs to use extra energy to defrost the outside unit (with resistive electric heating). The defrosting is driven by sensors, but rarely happens more than e.g. once an hour for 5 minutes at a time. Heat pumps really do win over resistive electric heating on everything except initial cost, and that's not even hard -- resistive electric heating is very wasteful.
bng8 2y ago
Most energy is generated from steam that has a terrible efficiency of 40%
exar0815 2y ago
At least where I live, the Steam is either reused from thermal power plant waste heat which would be evaporated off anyways, or its the heat directly produced from specialised combined electric/thermal gas plants (Blockheizkraftwerk). Also, general industrial waste heat is sometimes used (glass plants e.g).
someuser2345 2y ago
Most electricity is generated by using steam to turn turbines, right? So it definitely seems more efficient to just use the steam directly, instead of converting it to electrical energy and then converting it back to heat.
- proee 2y ago
  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.
  - dietr1ch 2y ago
    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.
    - abeppu 2y ago
      > 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.
      - wafflemaker 2y ago
        In many places in the world people don't live on ranches or in 1000 m² houses, but in 80-150 m² twin houses or even flats. In such tighter conditions, you can easily have enough inhabitants per km² that it would justify building small mobile nuclear reactors. Who would like to live next to a reactor if it can melt down? Well, you have reactors using fuel pellets locked in marbles that due to their diameter can never meltdown.
jsiepkes 2y ago
> Electrical transmission systems are roughly 85% efficient to the consumer; Electrical generation itself isn't a 100% efficient. For example a gas powered electricity plant is about 60% efficient for generating electricity. Generating heat from gas is far more efficient. Then again if you use the electricity not for direct heating but for example to power a heatpump on the other end (i.e. you use the electricity to extract heat from the air) then it could be more efficient.
perihelions 2y ago
Yes: very low temperature steam is useless from a thermodynamic perspective, cannot be used to perform (meaningful amounts of) work or generate electricity. When sourced a waste byproduct of an electric power plant, it's essentially free—it has no other economic value. There's zero opportunity cost of "you could use it for some other purpose instead".
- pjc50 2y ago
  Sadly this article doesn't make it clear whether it's waste steam from electricity generation or steam made explicitly for this purpose. It also doesn't specify what the fuel is now - it used to be coal, is that still the case? Wikipedia says "Approximately 30% of the ConEd steam system's installed capacity and 50% of the annual steam generated comes from cogeneration" i.e waste steam, which is .. half good, I suppose. It also gives https://web.archive.org/web/20101207021857/http://coned.com/PublicIssues/PDF/Steam%20Long%20Range%20Plan%20Final%20December%202010.pdf https://web.archive.org/web/20101207021857/http://coned.com/... which I guess has the rest of the details in.
- bluGill 2y ago
  There is cost though - the pipes needed to get steam someplace are not free. Those pipes can explode when things go wrong so people can die. How you add those costs up is a debatable question, but it isn't free.
bob1029 2y ago
https://en.wikipedia.org/wiki/Cogeneration https://en.wikipedia.org/wiki/Cogeneration
jszymborski 2y ago
Not my expertise, but my understanding is that district heating is a very very efficient way to store electricity, such that the inefficiencies in transmission are mitigated in part by the storage efficiency. This allows you to more reliably depend on energy sources that don't have 100% uptime. That said, I think most of this applies to heated water, not steam.
LeifCarrotson 2y ago
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 some of that heat turns the turbine, there's still a lot left that gets lost to the condenser or to the exhaust flue and atmosphere. However, that's where steam distribution is awesome: It enables cogeneration, where some of the waste heat from electricity production can be efficiently used by heating industries. The electrical plant requires supercritical steam at 1000F and 1000 PSI, but the steam network only needs steam at ~150 PSI and 350F, which still has a lot of energy in it from the burners but is of comparatively little use to the turbine.
- riggsdk 2y ago
  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.
  - z2 2y ago
    I feel like this could be a nice high school physics test question. Realistically, I don't think HV lines have much energy loss, owing to the use of high voltage in the first place as a means of minimizing loss. Then there are considerations for air resistance in the tubes, an almost 100% effective insulator, and all those real world issues of gnarly general maintenance. Almost all electricity run through computers are basically resistance losses at the end of the day, so data centers and crypto miners on the other hand...
    - lucb1e 2y ago
      Could not find the answer, kept getting general pages about how much current a wire can pass (without the result even containing the keyword I looked for, like temperature or heat or warm). To still have some indication of whether this is an interesting thing to keep looking into, ChatGPT says: > Typically, high-voltage transmission lines are designed to operate at temperatures of around 75 to 100°C (167 to 212°F). However, under heavy loads, they can sometimes reach up to 150°C (302°F), but this is usually the upper limit for safe operation. If that's a core temperature then the insulation might not make it significant, but if the outside leaks this much... I might not mind paying myself for a plastic tube and a fan to use around the line if I lived near one. Okay okay, it'll be more complicated than that, but still: free energy? And you're doing the power company a favor by decreasing the resistance in the case of most metals (https://www.engineeringtoolbox.com/resistivity-conductivity-d_418.html https://www.engineeringtoolbox.com/resistivity-conductivity-...) including copper which https://en.wikipedia.org/wiki/High-voltage_cable https://en.wikipedia.org/wiki/High-voltage_cable says they're made of
nine_k 2y ago
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.
- calaphos 2y ago
  It's not quite waste heat because the cold side of thermal power plants wants to be colder than district heating temperatures for best efficiency. There is some loss in electrical efficiency compared to non cogeneration plants, but the combined efficiency is a lot higher.
hwillis 2y ago
> 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 <1112 BTUs per pound vs room temperature will condense, so the heat value of a megapound of steam is at least 325,895 kWh. That's a marginal cost of 1 cent to 3 cents per MMBtu or 3.5 cents to 11 cents per MWh. The hookup cost ($3,555) is much smaller than the cost of the steam ($13k-$44k per the article). 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.
glenstein 2y ago
>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.
- wrsh07 2y ago
  Maybe this just makes your point, but solar panels being 20% efficient is about "how efficiently it converts energy from the sun into usable electricity" All that matters is the actual power generation since there's no marginal utility of "what else we would use that space for" (unless you're consuming farmland etc for the solar panels)
  - immibis 2y ago
    Ah, but a thermal solar panel is more like 60% efficient, and it's built of glass, black spray paint and a garden hose. If the ultimate goal is to heat something with sunlight, you know which approach is the best. Several times as much area coated in special silicon stuff, or.... garden hose spray-painted black. If the purposes are mixed, of course a photovoltaic panel can generate electricity for many purposes, while sunlight shining on a garden hose can only heat water. So it might be a more useful system, even more cost-effective, despite being much less thermally efficient. It's the same with burning things to make heat, versus burning them for electricity and then using electric heaters.
deleted 2y ago
[deleted]
cship2 2y ago
Steam is Carrington event resistant not electric system.
tracker1 2y ago
Where/how is the electricity sourced in a given case is probably worth consideration. If you have alternative sources for generation of steam vs generation of electricity, the methods/approach may vary. Not to mention the impact of the equipment necessary, the build process, availability and dependency on supply lines should all be considered.
mystified5016 2y ago
If you had industry nearby like a foundry or glassworks that throws off unimaginable waste heat, you can pump that heat into homes instead of the atmosphere.

walrus01 2y ago

In terms of thermodynamics, a electric resistive heater is 100% efficient, but if the measurement is how many BTU of heating you can put into a room in a day with a certain amount of watt hours, a modern heat pump will always beat it. Also of course 100% electric.

graemep 2y ago
A heat pump is more than 100% efficient on that measure. I am not sure about "always". Does it not depend on the temperature difference? The use cases for steam seem to be where you need more than room heating though: the first paragraph mentions sterilising medical equipment, humidity control, and washing.
- walrus01 2y ago
  My understanding is that it varies by temperature difference, but there's specialized series of heat pumps which work "okay" with very cold outside temperatures, even down to -25C, which are becoming popular to replace oil tank heating systems in Atlantic Canada. Apparently even when operating at -20C outside air they're still more efficient than electric baseboard heating. I don't know of any of the customers of the steam system in downtown Vancouver that use it for sterilization purposes, it connects almost exclusively large office towers. There's no hospital or medical facilities connected to it.
- yencabulator 2y ago
  > I am not sure about "always". Does it not depend on the temperature difference? My understanding: A heat pump is always better than resistive electric heating. Sometimes a outside air using heat pump needs to use extra energy to defrost the outside unit (with resistive electric heating). The defrosting is driven by sensors, but rarely happens more than e.g. once an hour for 5 minutes at a time. Heat pumps really do win over resistive electric heating on everything except initial cost, and that's not even hard -- resistive electric heating is very wasteful.

bng8 2y ago

Most energy is generated from steam that has a terrible efficiency of 40%

exar0815 2y ago

At least where I live, the Steam is either reused from thermal power plant waste heat which would be evaporated off anyways, or its the heat directly produced from specialised combined electric/thermal gas plants (Blockheizkraftwerk). Also, general industrial waste heat is sometimes used (glass plants e.g).

someuser2345 2y ago

Most electricity is generated by using steam to turn turbines, right? So it definitely seems more efficient to just use the steam directly, instead of converting it to electrical energy and then converting it back to heat.

proee 2y ago
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.
- dietr1ch 2y ago
  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.
  - abeppu 2y ago
    > 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.
    - wafflemaker 2y ago
      In many places in the world people don't live on ranches or in 1000 m² houses, but in 80-150 m² twin houses or even flats. In such tighter conditions, you can easily have enough inhabitants per km² that it would justify building small mobile nuclear reactors. Who would like to live next to a reactor if it can melt down? Well, you have reactors using fuel pellets locked in marbles that due to their diameter can never meltdown.

jsiepkes 2y ago

> Electrical transmission systems are roughly 85% efficient to the consumer; Electrical generation itself isn't a 100% efficient. For example a gas powered electricity plant is about 60% efficient for generating electricity. Generating heat from gas is far more efficient. Then again if you use the electricity not for direct heating but for example to power a heatpump on the other end (i.e. you use the electricity to extract heat from the air) then it could be more efficient.

perihelions 2y ago

Yes: very low temperature steam is useless from a thermodynamic perspective, cannot be used to perform (meaningful amounts of) work or generate electricity. When sourced a waste byproduct of an electric power plant, it's essentially free—it has no other economic value. There's zero opportunity cost of "you could use it for some other purpose instead".

pjc50 2y ago
Sadly this article doesn't make it clear whether it's waste steam from electricity generation or steam made explicitly for this purpose. It also doesn't specify what the fuel is now - it used to be coal, is that still the case? Wikipedia says "Approximately 30% of the ConEd steam system's installed capacity and 50% of the annual steam generated comes from cogeneration" i.e waste steam, which is .. half good, I suppose. It also gives https://web.archive.org/web/20101207021857/http://coned.com/PublicIssues/PDF/Steam%20Long%20Range%20Plan%20Final%20December%202010.pdf https://web.archive.org/web/20101207021857/http://coned.com/... which I guess has the rest of the details in.
bluGill 2y ago
There is cost though - the pipes needed to get steam someplace are not free. Those pipes can explode when things go wrong so people can die. How you add those costs up is a debatable question, but it isn't free.

bob1029 2y ago

https://en.wikipedia.org/wiki/Cogeneration https://en.wikipedia.org/wiki/Cogeneration

jszymborski 2y ago

Not my expertise, but my understanding is that district heating is a very very efficient way to store electricity, such that the inefficiencies in transmission are mitigated in part by the storage efficiency. This allows you to more reliably depend on energy sources that don't have 100% uptime. That said, I think most of this applies to heated water, not steam.

LeifCarrotson 2y ago

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 some of that heat turns the turbine, there's still a lot left that gets lost to the condenser or to the exhaust flue and atmosphere. However, that's where steam distribution is awesome: It enables cogeneration, where some of the waste heat from electricity production can be efficiently used by heating industries. The electrical plant requires supercritical steam at 1000F and 1000 PSI, but the steam network only needs steam at ~150 PSI and 350F, which still has a lot of energy in it from the burners but is of comparatively little use to the turbine.

riggsdk 2y ago
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.
- z2 2y ago
  I feel like this could be a nice high school physics test question. Realistically, I don't think HV lines have much energy loss, owing to the use of high voltage in the first place as a means of minimizing loss. Then there are considerations for air resistance in the tubes, an almost 100% effective insulator, and all those real world issues of gnarly general maintenance. Almost all electricity run through computers are basically resistance losses at the end of the day, so data centers and crypto miners on the other hand...
  - lucb1e 2y ago
    Could not find the answer, kept getting general pages about how much current a wire can pass (without the result even containing the keyword I looked for, like temperature or heat or warm). To still have some indication of whether this is an interesting thing to keep looking into, ChatGPT says: > Typically, high-voltage transmission lines are designed to operate at temperatures of around 75 to 100°C (167 to 212°F). However, under heavy loads, they can sometimes reach up to 150°C (302°F), but this is usually the upper limit for safe operation. If that's a core temperature then the insulation might not make it significant, but if the outside leaks this much... I might not mind paying myself for a plastic tube and a fan to use around the line if I lived near one. Okay okay, it'll be more complicated than that, but still: free energy? And you're doing the power company a favor by decreasing the resistance in the case of most metals (https://www.engineeringtoolbox.com/resistivity-conductivity-d_418.html https://www.engineeringtoolbox.com/resistivity-conductivity-...) including copper which https://en.wikipedia.org/wiki/High-voltage_cable https://en.wikipedia.org/wiki/High-voltage_cable says they're made of

nine_k 2y ago

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.

calaphos 2y ago
It's not quite waste heat because the cold side of thermal power plants wants to be colder than district heating temperatures for best efficiency. There is some loss in electrical efficiency compared to non cogeneration plants, but the combined efficiency is a lot higher.

hwillis 2y ago

> 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 <1112 BTUs per pound vs room temperature will condense, so the heat value of a megapound of steam is at least 325,895 kWh. That's a marginal cost of 1 cent to 3 cents per MMBtu or 3.5 cents to 11 cents per MWh. The hookup cost ($3,555) is much smaller than the cost of the steam ($13k-$44k per the article). 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.

glenstein 2y ago

>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.

wrsh07 2y ago
Maybe this just makes your point, but solar panels being 20% efficient is about "how efficiently it converts energy from the sun into usable electricity" All that matters is the actual power generation since there's no marginal utility of "what else we would use that space for" (unless you're consuming farmland etc for the solar panels)
- immibis 2y ago
  Ah, but a thermal solar panel is more like 60% efficient, and it's built of glass, black spray paint and a garden hose. If the ultimate goal is to heat something with sunlight, you know which approach is the best. Several times as much area coated in special silicon stuff, or.... garden hose spray-painted black. If the purposes are mixed, of course a photovoltaic panel can generate electricity for many purposes, while sunlight shining on a garden hose can only heat water. So it might be a more useful system, even more cost-effective, despite being much less thermally efficient. It's the same with burning things to make heat, versus burning them for electricity and then using electric heaters.

deleted 2y ago

[deleted]

cship2 2y ago

Steam is Carrington event resistant not electric system.

tracker1 2y ago

Where/how is the electricity sourced in a given case is probably worth consideration. If you have alternative sources for generation of steam vs generation of electricity, the methods/approach may vary. Not to mention the impact of the equipment necessary, the build process, availability and dependency on supply lines should all be considered.

mystified5016 2y ago

If you had industry nearby like a foundry or glassworks that throws off unimaginable waste heat, you can pump that heat into homes instead of the atmosphere.