6 ms·

Following this logic, I often thought electric heaters are a waste of energy since they perform no computation. But a French company is having a go at this: ht

Following this logic, I often thought electric heaters are a waste of energy since they perform no computation. But a French company is having a go at this: https://www.qarnot.com/computing-heater_qh-1/ https://www.qarnot.com/computing-heater_qh-1/

mehrdadn 7y ago
Confused, could you explain? A heater that puts its energy into something other than heating is just being inefficient at heating, right? Shouldn't you want it to put 100% of its energy into heating?
- greiskul 7y ago
  Well, not really, let's say we want to heat a room to 25 degrees Celsius. If we are converting 100% of the electricity used to heat, it will take X energy. If we use the energy for computing instead, and use the waste heat to heat the room, it will take maybe a little more energy. But the thing is, the computing is valuable, and with the money we can gain by "renting" the computing, we can buy more electricity, so we come out on top. Now, like someone else commented, if you really want to heat an environment, the traditional resistance heating is not the best solution. With a heat pump, you can cheat, and get an efficiency of over 100% (because instead of using the energy to heat the room, you are using the energy to take heat from somewhere else and also put it in the room).
  - mehrdadn 7y ago
    Are you trying to be energy-efficient or are you trying to be cost-efficient? I thought the former but it seems you mean the latter.
  - deleted 7y ago
    [deleted]
- Sharlin 7y ago
  To very good approximation, 100% of the energy used by a contemporary computer is turned to heat. The amount of negentropy generated by the computations is utterly dwarfed by the increase in entropy in the computer's surroundings. Computers are space heaters that happen to do some calculations as a side effect.
  - rightbyte 7y ago
    I wonder if WD and friends do generative braking on the hard drives.
    - zepearl 7y ago
      :) Regenerative braking when the arm of the HDD starts getting near the target track.
    - lovemenot 7y ago
      Spin them all up when the wind blows and convert their kinetic energy to power during a lull.
  - mehrdadn 7y ago
    I do realize that and I still don't get how doing computation is supposed to increase the energy efficiency of heating. Are you trying to reduce wasted energy while heating by diverting it to computation, or are you trying to avoid wasted energy in computing by utilizing the otherwise-wasted heat? It seems like you're optimizing the cost efficiency of computation while claiming it improves the energy efficiency of heating...
    - foota 7y ago
      Computing is heating, but with benefits, to a rough approximation. The components inside the computer do something with the electricity, which results in it being turned into heat. So by doing useful computing and using the created heat as a result for heating something, you've effectively made the heating free, to the degree you can use the computing for something useful.
ineedasername 7y ago
Couldn't the heat also be used to generate more electricity?
- NickNameNick 7y ago
  No, because you need to be able to exploit a temperature difference to convert heat into other forms of energy. Conversion efficiency is proportional to the difference in temperature, so for most wate-heat scenarios, electricity generation is either non-functional, or barely functional, but impractical. In a lot of scenarios you end up interfering with the efficiency or longevity of whatever you were trying to cool in the first place.
CobrastanJorji 7y ago
That's amazing, but what sort of computation does it do while heating? Are you supposed to queue up your rendering until it's cold outside, or does it mine bitcoins?
- on_and_off 7y ago
  I hope it does something more useful than mining bitcoins. There are many research projects that could use some more computing power and that would bring a gain to humanity.
  - wolco 7y ago
    Powering billions of dollars worth of bitcoin not worthy enough? I get the feeling if money was not involved it may qualify as a worthy research project.
    - on_and_off 7y ago
      exactly what would be its value outside of the monetary one for you ?
    - ineedasername 7y ago
      It's not the money. Dedicate the computational power to @Folding and it would be worthwhile even if they also paid people. Personally if I had to choose between generating data for medical research or hash functions for proof of work, I'd go for the medical research. Though I'm not sure we really have to choose-- aren't there coins in the works that are trying to address the massive power consumption issue?
nordsieck 7y ago
> Following this logic, I often thought electric heaters are a waste of energy since they perform no computation. That's true of resistive heating. Heat pumps are more efficient.
- pyrale 7y ago
  Also they can work both ways.
Analemma_ 7y ago
This is not true. A computer heater can only ever be 100% efficient, but most electric heaters are actually heat pumps and can be up to 400% efficient, depending on conditions. Heating your home with bitcoin miners (or any other computing device) is a staggering waste of energy.
- cooljacob204 7y ago
  Can you go into more details about what a heatpump is and how something can be 400% efficient?
  - repiret 7y ago
    A heat pump is basically an air conditioner running backwards - it runs uncompressed refrigerant through a radiator outside to pick up heat from the outdoors, and compressed refrigerant through a radiator indoors to release the heat. Because they can move more heat than they dissipate (and some of the dissipated heat is indoors anyway) they can be more than 100% efficient. (edited to fix compressed/uncompressed sides) But I'd venture to say the statement "most electric heaters are heatpumps" is in fact false. There are a lot of heat pumps in the world, but there are also a lot of pure resistive electric heaters. I suspect that most things people call electric heaters are resistive electric heaters.
    - ithkuil 7y ago
      (disclaimer: physics noob) If a Stirling engine can be operate at 50% efficiency and a heap pump can operate at 400% efficiency, could we take a source of heat (e.g. heat side product of computation instead of burning fuel) use it to power the Stirling engine and use the movement of the Stirling engine to power a heat pump and thus turn computation into house heating at effective 200% efficiency? (under whatever assumptions were made in the claim of 400% efficient heat pump; I assume the temperature differential is key; I also assume that the optimal cold side for the stiling engine and for the heat pump is quite different, but you can tap one in cold air and the other in deep ground)

mehrdadn 7y ago

Confused, could you explain? A heater that puts its energy into something other than heating is just being inefficient at heating, right? Shouldn't you want it to put 100% of its energy into heating?

greiskul 7y ago
Well, not really, let's say we want to heat a room to 25 degrees Celsius. If we are converting 100% of the electricity used to heat, it will take X energy. If we use the energy for computing instead, and use the waste heat to heat the room, it will take maybe a little more energy. But the thing is, the computing is valuable, and with the money we can gain by "renting" the computing, we can buy more electricity, so we come out on top. Now, like someone else commented, if you really want to heat an environment, the traditional resistance heating is not the best solution. With a heat pump, you can cheat, and get an efficiency of over 100% (because instead of using the energy to heat the room, you are using the energy to take heat from somewhere else and also put it in the room).
- mehrdadn 7y ago
  Are you trying to be energy-efficient or are you trying to be cost-efficient? I thought the former but it seems you mean the latter.
- deleted 7y ago
  [deleted]
Sharlin 7y ago
To very good approximation, 100% of the energy used by a contemporary computer is turned to heat. The amount of negentropy generated by the computations is utterly dwarfed by the increase in entropy in the computer's surroundings. Computers are space heaters that happen to do some calculations as a side effect.
- rightbyte 7y ago
  I wonder if WD and friends do generative braking on the hard drives.
  - zepearl 7y ago
    :) Regenerative braking when the arm of the HDD starts getting near the target track.
  - lovemenot 7y ago
    Spin them all up when the wind blows and convert their kinetic energy to power during a lull.
- mehrdadn 7y ago
  I do realize that and I still don't get how doing computation is supposed to increase the energy efficiency of heating. Are you trying to reduce wasted energy while heating by diverting it to computation, or are you trying to avoid wasted energy in computing by utilizing the otherwise-wasted heat? It seems like you're optimizing the cost efficiency of computation while claiming it improves the energy efficiency of heating...
  - foota 7y ago
    Computing is heating, but with benefits, to a rough approximation. The components inside the computer do something with the electricity, which results in it being turned into heat. So by doing useful computing and using the created heat as a result for heating something, you've effectively made the heating free, to the degree you can use the computing for something useful.

ineedasername 7y ago

Couldn't the heat also be used to generate more electricity?

NickNameNick 7y ago
No, because you need to be able to exploit a temperature difference to convert heat into other forms of energy. Conversion efficiency is proportional to the difference in temperature, so for most wate-heat scenarios, electricity generation is either non-functional, or barely functional, but impractical. In a lot of scenarios you end up interfering with the efficiency or longevity of whatever you were trying to cool in the first place.

CobrastanJorji 7y ago

That's amazing, but what sort of computation does it do while heating? Are you supposed to queue up your rendering until it's cold outside, or does it mine bitcoins?

on_and_off 7y ago
I hope it does something more useful than mining bitcoins. There are many research projects that could use some more computing power and that would bring a gain to humanity.
- wolco 7y ago
  Powering billions of dollars worth of bitcoin not worthy enough? I get the feeling if money was not involved it may qualify as a worthy research project.
  - on_and_off 7y ago
    exactly what would be its value outside of the monetary one for you ?
  - ineedasername 7y ago
    It's not the money. Dedicate the computational power to @Folding and it would be worthwhile even if they also paid people. Personally if I had to choose between generating data for medical research or hash functions for proof of work, I'd go for the medical research. Though I'm not sure we really have to choose-- aren't there coins in the works that are trying to address the massive power consumption issue?

nordsieck 7y ago

> Following this logic, I often thought electric heaters are a waste of energy since they perform no computation. That's true of resistive heating. Heat pumps are more efficient.

pyrale 7y ago
Also they can work both ways.

Analemma_ 7y ago

This is not true. A computer heater can only ever be 100% efficient, but most electric heaters are actually heat pumps and can be up to 400% efficient, depending on conditions. Heating your home with bitcoin miners (or any other computing device) is a staggering waste of energy.

cooljacob204 7y ago
Can you go into more details about what a heatpump is and how something can be 400% efficient?
- repiret 7y ago
  A heat pump is basically an air conditioner running backwards - it runs uncompressed refrigerant through a radiator outside to pick up heat from the outdoors, and compressed refrigerant through a radiator indoors to release the heat. Because they can move more heat than they dissipate (and some of the dissipated heat is indoors anyway) they can be more than 100% efficient. (edited to fix compressed/uncompressed sides) But I'd venture to say the statement "most electric heaters are heatpumps" is in fact false. There are a lot of heat pumps in the world, but there are also a lot of pure resistive electric heaters. I suspect that most things people call electric heaters are resistive electric heaters.
  - ithkuil 7y ago
    (disclaimer: physics noob) If a Stirling engine can be operate at 50% efficiency and a heap pump can operate at 400% efficiency, could we take a source of heat (e.g. heat side product of computation instead of burning fuel) use it to power the Stirling engine and use the movement of the Stirling engine to power a heat pump and thus turn computation into house heating at effective 200% efficiency? (under whatever assumptions were made in the claim of 400% efficient heat pump; I assume the temperature differential is key; I also assume that the optimal cold side for the stiling engine and for the heat pump is quite different, but you can tap one in cold air and the other in deep ground)