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Microsoft's underwater data centre resurfaces after two years

bbc.co.uk

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Re: Microsoft's underwater data centre resurfaces after two years

#71

Post by mlyle »

JumpCrisscross wrote: post #40
StavrosK wrote: post #37

Earlier quoted context omitted.

The issue is CO2, though, not heat per se. Yes, the two are correlated, but if you use renewables to power your things, it doesn't really matter how much heat you generate. Please correct me if I'm wrong.

> it doesn't really matter how much heat you generate Doesn’t matter is strong. It won’t in the short term. But as we continue increasing our energy use as a species, the simple thermal problem of waste-heat management will certainly surface.

If you use renewables, you're using heat that is already around on the planet. As long as you don't change planetary albedo, equilibrium temperature is the same.

Of course, heating water locally, etc, can cause its own environmental impacts.

Re: Microsoft's underwater data centre resurfaces after two years

#72

Post by mlyle »

serjester wrote: post #46
jacquesm wrote: post #10

Why heat the oceans indirectly when you can just place the heatsource directly in them? Much less chance of losing precious ergs. Seriously though, what is the direct ecological impact of doing this at scale, would the local increase in temperature have an immediate effect on the life around it? If so how much of an impact? What about the effect on surface life and life in intermediary layers of the water? After all,…

It takes about 80 watts to heat up a liter of water 1° celsius. Global data centers used about 4.16 x 10^14 watts last year [1]. Let's assume we still have a lot more data centers to build so bump that number up 10,000X. Assuming every watt of energy is actually converted to heat and we moved every data center on earth underwater it'd raise the temperate of the oceans (1.3x 10^21 liters) about 0.01°C. This is a very…

Conflating power and energy, and not considering the amount of heat that would be dissipated away, completely destroy any meaning this math would have.

Re: Microsoft's underwater data centre resurfaces after two years

#73

Post by jerrysievert »

jacquesm wrote: post #14
kzrdude wrote: post #11

In the final product, you could build the data center underwater in-place, and have the servers partially accessible - they only need to be connected to the structure in one end, and can be surrounded by water on all other sides. (Visual idea - the data center parts are like fingers on the main structure).

Any seal in that construct would be a single-point-of-failure for the whole, not just one fraction.

and if there are any salmon in the area, any sea lion could also be quite dangerous to the whole.

Re: Microsoft's underwater data centre resurfaces after two years

#74

Post by TheNorthman »

mrfredward wrote: post #59
serjester wrote: post #46

Earlier quoted context omitted.

It takes about 80 watts to heat up a liter of water 1° celsius. Global data centers used about 4.16 x 10^14 watts last year [1]. Let's assume we still have a lot more data centers to build so bump that number up 10,000X. Assuming every watt of energy is actually converted to heat and we moved every data center on earth underwater it'd raise the temperate of the oceans (1.3x 10^21 liters) about 0.01°C. This is a very…

>It takes about 80 watts to heat up a liter of water 1° celsius You're confusing power and energy here.

The formula for calculating this is: Q = c_p * d * V * (ΔT). Assuming an isobaric specific heat capacity of 4.18 J/(g K) and a density of 1.00 g/cm^3, heating a liter of water 1.00 K would take 4.18 kJ.

Giving OP's number for the volume of water in the ocean, heating the ocean 0.01 K would be 5.4 * 10^22 J. Assuming 365 days in a year, that's 1.7 * 10^15 W, an order of magnitude less than OPs figure for datacenter power-usage.

Re: Microsoft's underwater data centre resurfaces after two years

#76

Post by shawkinaw »

eloff wrote: post #67
shawkinaw wrote: post #64

Earlier quoted context omitted.

> And HVAC systems create far more waste heat than they do cooling, so this passive cooling will just be moving the source heat to the water, not dumping extra waste heat as well. Where do you get that idea? A typical EER 12 air conditioner will move 3.5x the heat energy that it consumes (COP = 3.5) [0]. [0] https://www.engineeringtoolbox.com/cop-eer-d_409.html

I don't see the contradiction. The heat it moves plus the heat generated through inefficiency. It's always > heat moved.

I guess it depends what you mean by "waste heat". I consider the waste heat as the "extra" heat/energy on top of the heat moved. But even if you consider all the heat as waste heat, calling 30% more "far" more seems like an exaggeration.

Re: Microsoft's underwater data centre resurfaces after two years

#77

Post by vidarh »

serjester wrote: post #46
jacquesm wrote: post #10

Why heat the oceans indirectly when you can just place the heatsource directly in them? Much less chance of losing precious ergs. Seriously though, what is the direct ecological impact of doing this at scale, would the local increase in temperature have an immediate effect on the life around it? If so how much of an impact? What about the effect on surface life and life in intermediary layers of the water? After all,…

It takes about 80 watts to heat up a liter of water 1° celsius. Global data centers used about 4.16 x 10^14 watts last year [1]. Let's assume we still have a lot more data centers to build so bump that number up 10,000X. Assuming every watt of energy is actually converted to heat and we moved every data center on earth underwater it'd raise the temperate of the oceans (1.3x 10^21 liters) about 0.01°C. This is a very…

> It takes about 80 watts to heat up a liter of water 1° celsius.

1 calorie is by definition the energy requires to heat 1 gram of water 1°C. In practice 1ml.

So ~1kcal to heat 1 liter of water 1°C

1 kcal is ~1.163 watt-hours.

Re: Microsoft's underwater data centre resurfaces after two years

#78

Post by whiw »

serjester wrote: post #46
jacquesm wrote: post #10

Why heat the oceans indirectly when you can just place the heatsource directly in them? Much less chance of losing precious ergs. Seriously though, what is the direct ecological impact of doing this at scale, would the local increase in temperature have an immediate effect on the life around it? If so how much of an impact? What about the effect on surface life and life in intermediary layers of the water? After all,…

It takes about 80 watts to heat up a liter of water 1° celsius. Global data centers used about 4.16 x 10^14 watts last year [1]. Let's assume we still have a lot more data centers to build so bump that number up 10,000X. Assuming every watt of energy is actually converted to heat and we moved every data center on earth underwater it'd raise the temperate of the oceans (1.3x 10^21 liters) about 0.01°C. This is a very…

This seems to confuse Power with Energy. Watts measure Power, which is a rate of Energy.

The specific heat of water is 4182 Joules/kg and its density is close to 1kg/litre, so 4.128 kJ (Energy) will be required to heat 1 litre of water by 1 degree C.

The temperature rise of the oceans will be complicated to work out. Taking the OPs figures, 4.16x10^14 watts / 1.3x10^21 litres gives 3.2x10^-7 watts per litre of ocean, ie 0.32 microJoules of energy added to the oceans every second. The temperature rise of the oceans will depend on how quickly it can dissipate this heat. What are relevant the heat loss mechanisms? Evaporation just moves the problem to the atmosphere. Conduction just moves it elsewhere on earth. Radiation will shift some of it to space (and some reflected back to the earth), but radiation is a property of the surface of the ocean, not of the bulk.

Re: Microsoft's underwater data centre resurfaces after two years

#79

Post by aaronbee »

t0mbstone wrote: post #68
serjester wrote: post #46

Earlier quoted context omitted.

It takes about 80 watts to heat up a liter of water 1° celsius. Global data centers used about 4.16 x 10^14 watts last year [1]. Let's assume we still have a lot more data centers to build so bump that number up 10,000X. Assuming every watt of energy is actually converted to heat and we moved every data center on earth underwater it'd raise the temperate of the oceans (1.3x 10^21 liters) about 0.01°C. This is a very…

You are making the assumption that moving data centers underwater would also come along with a 10,000-fold increase in the number of data centers? That seems like an unnecessarily hyperbolic approach. That would mean going from 8.4 million data centers to 840 billion data centers. I mean, come on... But hey, let's roll with it. What would be the effect on the environment if we literally had 10,000 times more data cen…

I believe the GP's point is that even with a 10,000x increase in data center energy consumption, the effect on ocean temperature is tiny.

Re: Microsoft's underwater data centre resurfaces after two years

#80

Post by bfieidhbrjr »

vidarh wrote: post #77
serjester wrote: post #46

Earlier quoted context omitted.

It takes about 80 watts to heat up a liter of water 1° celsius. Global data centers used about 4.16 x 10^14 watts last year [1]. Let's assume we still have a lot more data centers to build so bump that number up 10,000X. Assuming every watt of energy is actually converted to heat and we moved every data center on earth underwater it'd raise the temperate of the oceans (1.3x 10^21 liters) about 0.01°C. This is a very…

> It takes about 80 watts to heat up a liter of water 1° celsius. 1 calorie is by definition the energy requires to heat 1 gram of water 1°C. In practice 1ml. So ~1kcal to heat 1 liter of water 1°C 1 kcal is ~1.163 watt-hours.

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