Americans across multiple states are being urged to conserve water as drought conditions intensify, reservoirs shrink, and utilities issue increasingly urgent warnings. At the same time, a different kind of consumer is quietly demanding unprecedented...
The issue is heat. If your data center consumes 100 megawatts, that’s 100 megawatts of electricity that turns into 100 megawatts of heat. Part of the challenge of a data center is getting rid of that heat and keeping the servers cool.
There’s a fun little principle called latent heat in phase change. To take 1 g of water and heat it from just above freezing to just below boiling consumes about 100 calories of energy. To then boil it, to raise it just a fraction of a degree and turn it into steam, takes another 433 calories of energy. So if your data center has 100 megawatts of heat to get rid of, turning water into vapor is a great way to get rid of it.
You don’t actually even need to boil the water, if you take warm water and spray it into the air, some of it will evaporate and the water that comes back on the ground is significantly colder than what you sprayed in the air. This is harnessed with a machine called a cooling tower, it’s a big boxy thing that has a ton of little waterfalls and wet plates inside it while a giant fan blows tons of air through it. You pour warm water in, some of it evaporates, the water that comes out is much colder. Many buildings use this as part of their air conditioning system.
But when that water evaporates, you need more water to replace it. And that’s why they say data centers consume water. The water isn’t destroyed, but it is released into the atmosphere as steam or humidity and thus is no longer usable until it rains again. Which, depending on your climate, may be sometime away or may be some distance away.
They (usually) pump water out of the ground because they don’t need it to be filtered or treated. The hot towers turn liquid water into vapor, which they (usually) pump outside. The vapor floats into the air and then gets carried away and dumped somewhere else, like the ocean.
Yeah, man. Consumed in the same way that we mean water is consumed in every other context. Doesn’t change the fact that the ground water is now sky water. Ground water takes months to decades to replenish, using it isn’t harmless to the ecosystems you take it from.
There’s no reason AI datacenters couldn’t be closed loop systems and just reuse the water. There are a multitude of ways water could be used more efficiently, it just has to be regulated.
The problem is that it accelerates the cycle of freshwater to undrinkable salt water (most rains down into the ocean) while the cycle taking that water back to clean watersheds is no faster than before, which contributes to depletion of limited drinking water - especially since municipalities are often all too eager to strike deals with data centers to provide cheap hookups to the drinking water supply.
The logic of saying that it’s all staying in the water cycle feels kinda like dumping all the food in your fridge into a septic tank and saying well none of the atoms where destroyed and it’ll all come back through the grocery store in a millenia. Sure in the grand scheme it’s a big closed loop, but the loop moves slowly and unevenly.
Not entirely. If it’s pumped from the water table, it can take many years for it to filter its way back in through the bedrock.
My dad had a house on a mountain and when his well went dry, I celebrated when it started raining. But then he said it wouldn’t matter, as that rain wouldn’t hit the water table for years, and it would just run off and away mostly.
We could start by using non pottable water in the first place. In Canada, no data centres use groundwater extraction because of stricter regulations. You can shake your fist at the clouds, but far better to lobby your government to pass regulations to protect groundwater.
Say, you wouldn’t have a problem if I dumped my household sewage in your municipal water supply, would you? After all, I’m technically not consuming any water - no molecules are being created or destroyed - just borrowing it for a few hours.
it’s basically evaporative cooling. so they could condense it but that takes energy. energy takes money. money takes from profit. and the water is a public resource and capitalists hate the public anyway.
Yeah that’s what I don’t get about all of this. Why can’t they recycle this water if it’s just being used for cooling. Why must it always be fresh water?
Because recycling the water would require condensing it, and the laws of thermodynamics necessitates that the energy that was taken away into the water by the phase change from water to vapor must be taken back out of the vapor in order to change it back into water.
That’s to say, in order to get the water back that was evaporated to cool something, you must cool the water the same amount that it cooled your other thing. This makes recovering the water completely pointless as you have to do the exact same amount of cooling again to recover it.
Data centers use evaporative cooling because it’s cheap. Not recovering the water is what makes it cheap. They can use cooling methods that don’t rely on disposing of water to the atmosphere (like heat pumps), but it’s not cheap.
Data centers use evaporative cooling because it’s cheap. Not recovering the water is what makes it cheap.
This is where regulations need to step in. The extra cost of non-evaporarive cooling is not going to make or break the datacenter, but it might cut into the CEO’s bonus. Make them pay for it! They’ve got the money.
This is the part where you need to realize that regulations only come into play long after devastating impacts occur and can’t be denied any longer (or, more accurately, until they can be denied again. See, the state of anti-trust in the US). Capitalism only exists because it can foist externalities onto the public. And capitalism will do anything to avoid paying for the externalities that allow them to “generate” profits.
Consumed? Where did the water go? I’m guessing it’s still water.
The issue is heat. If your data center consumes 100 megawatts, that’s 100 megawatts of electricity that turns into 100 megawatts of heat. Part of the challenge of a data center is getting rid of that heat and keeping the servers cool.
There’s a fun little principle called latent heat in phase change. To take 1 g of water and heat it from just above freezing to just below boiling consumes about 100 calories of energy. To then boil it, to raise it just a fraction of a degree and turn it into steam, takes another 433 calories of energy. So if your data center has 100 megawatts of heat to get rid of, turning water into vapor is a great way to get rid of it.
You don’t actually even need to boil the water, if you take warm water and spray it into the air, some of it will evaporate and the water that comes back on the ground is significantly colder than what you sprayed in the air. This is harnessed with a machine called a cooling tower, it’s a big boxy thing that has a ton of little waterfalls and wet plates inside it while a giant fan blows tons of air through it. You pour warm water in, some of it evaporates, the water that comes out is much colder. Many buildings use this as part of their air conditioning system. But when that water evaporates, you need more water to replace it. And that’s why they say data centers consume water. The water isn’t destroyed, but it is released into the atmosphere as steam or humidity and thus is no longer usable until it rains again. Which, depending on your climate, may be sometime away or may be some distance away.
They (usually) pump water out of the ground because they don’t need it to be filtered or treated. The hot towers turn liquid water into vapor, which they (usually) pump outside. The vapor floats into the air and then gets carried away and dumped somewhere else, like the ocean.
Exactly. The water isn’t destroyed, just put through it’s normal cycle.
Yeah, man. Consumed in the same way that we mean water is consumed in every other context. Doesn’t change the fact that the ground water is now sky water. Ground water takes months to decades to replenish, using it isn’t harmless to the ecosystems you take it from.
There’s no reason AI datacenters couldn’t be closed loop systems and just reuse the water. There are a multitude of ways water could be used more efficiently, it just has to be regulated.
And there’s no reason I couldn’t be a bicycle if you attached wheels to me. We’re talking about what is, not what could be.
So reach out to your representative to encourage them to implement regulations.
The problem is that it accelerates the cycle of freshwater to undrinkable salt water (most rains down into the ocean) while the cycle taking that water back to clean watersheds is no faster than before, which contributes to depletion of limited drinking water - especially since municipalities are often all too eager to strike deals with data centers to provide cheap hookups to the drinking water supply.
The logic of saying that it’s all staying in the water cycle feels kinda like dumping all the food in your fridge into a septic tank and saying well none of the atoms where destroyed and it’ll all come back through the grocery store in a millenia. Sure in the grand scheme it’s a big closed loop, but the loop moves slowly and unevenly.
Awesome analogy with the food dumping. Neatly illustrates what really is expended is the amount of (low) entropy.
Source?
https://arxiv.org/pdf/2304.03271
This is why regulation is so important. We (law makers) need to define the box AI datacenters can work inside.
Not entirely. If it’s pumped from the water table, it can take many years for it to filter its way back in through the bedrock.
My dad had a house on a mountain and when his well went dry, I celebrated when it started raining. But then he said it wouldn’t matter, as that rain wouldn’t hit the water table for years, and it would just run off and away mostly.
We could start by using non pottable water in the first place. In Canada, no data centres use groundwater extraction because of stricter regulations. You can shake your fist at the clouds, but far better to lobby your government to pass regulations to protect groundwater.
Oh well that makes it completely okay!
Say, you wouldn’t have a problem if I dumped my household sewage in your municipal water supply, would you? After all, I’m technically not consuming any water - no molecules are being created or destroyed - just borrowing it for a few hours.
it’s basically evaporative cooling. so they could condense it but that takes energy. energy takes money. money takes from profit. and the water is a public resource and capitalists hate the public anyway.
Yeah that’s what I don’t get about all of this. Why can’t they recycle this water if it’s just being used for cooling. Why must it always be fresh water?
Many of these facilities are using evaporation coolers. Which means the water just evaporates. And that ends up raining into the ocean later.
They’re going to cheap out in whatever way they can. Using a different cooling system, or using non-potable water isn’t going to be done voluntarily.
They evaporate it using cooling towers. Because it’s the cheapest way to shed heat.
Because recycling the water would require condensing it, and the laws of thermodynamics necessitates that the energy that was taken away into the water by the phase change from water to vapor must be taken back out of the vapor in order to change it back into water.
That’s to say, in order to get the water back that was evaporated to cool something, you must cool the water the same amount that it cooled your other thing. This makes recovering the water completely pointless as you have to do the exact same amount of cooling again to recover it.
Data centers use evaporative cooling because it’s cheap. Not recovering the water is what makes it cheap. They can use cooling methods that don’t rely on disposing of water to the atmosphere (like heat pumps), but it’s not cheap.
This is where regulations need to step in. The extra cost of non-evaporarive cooling is not going to make or break the datacenter, but it might cut into the CEO’s bonus. Make them pay for it! They’ve got the money.
This is the part where you need to realize that regulations only come into play long after devastating impacts occur and can’t be denied any longer (or, more accurately, until they can be denied again. See, the state of anti-trust in the US). Capitalism only exists because it can foist externalities onto the public. And capitalism will do anything to avoid paying for the externalities that allow them to “generate” profits.
It does have a touch of fear mongering. The water wouldn’t even be contaminated.
They evaporate it using cooling towers. Because it’s the cheapest way to shed heat.