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Why the new “reasoning” models might gobble up more electricity — at least in the short term

What happens when artificial intelligence takes some time to think?
The newest set of models from OpenAI, o1-mini and o1-preview, exhibit more “reasoning” than existing large language models and associated interfaces, which spit out answers to prompts almost instantaneously.
Instead, the new model will sometimes “think” for as long as a minute or two. “Through training, they learn to refine their thinking process, try different strategies, and recognize their mistakes,” OpenAI announced in a blog post last week. The company said these models perform better than their existing ones on some tasks, especially related to math and science. “This is a significant advancement and represents a new level of AI capability,” the company said.
But is it also a significant advancement in energy usage?
In the short run at least, almost certainly, as spending more time “thinking” and generating more text will require more computing power. As Erik Johannes Husom, a researcher at SINTEF Digital, a Norwegian research organization, told me, “It looks like we’re going to get another acceleration of generative AI’s carbon footprint.”
Discussion of energy use and large language models has been dominated by the gargantuan requirements for “training,” essentially running a massive set of equations through a corpus of text from the internet. This requires hardware on the scale of tens of thousands of graphical processing units and an estimated 50 gigawatt-hours of electricity to run.
Training GPT-4 cost “more than” $100 million OpenAI chief executive Sam Altman has said; the next generation models will likely cost around $1 billion, according to Anthropic chief executive Dario Amodei, a figure that might balloon to $100 billion for further generation models, according to Oracle founder Larry Ellison.
While a huge portion of these costs are hardware, the energy consumption is considerable as well. (Meta reported that when training its Llama 3 models, power would sometimes fluctuate by “tens of megawatts,” enough to power thousands of homes). It’s no wonder that OpenAI’s chief executive Sam Altman has put hundreds of millions of dollars into a fusion company.
But the models are not simply trained, they're used out in the world, generating outputs (think of what ChatGPT spits back at you). This process tends to be comparable to other common activities like streaming Netflix or using a lightbulb. This can be done with different hardware and the process is more distributed and less energy intensive.
As large language models are being developed, most computational power — and therefore most electricity — is used on training, Charlie Snell, a PhD student at University of California at Berkeley who studies artificial intelligence, told me. “For a long time training was the dominant term in computing because people weren’t using models much.” But as these models become more popular, that balance could shift.
“There will be a tipping point depending on the user load, when the total energy consumed by the inference requests is larger than the training,” said Jovan Stojkovic, a graduate student at the University of Illinois who has written about optimizing inference in large language models.
And these new reasoning models could bring that tipping point forward because of how computationally intensive they are.
“The more output a model produces, the more computations it has performed. So, long chain-of-thoughts leads to more energy consumption,” Husom of SINTEF Digital told me.
OpenAI staffers have been downright enthusiastic about the possibilities of having more time to think, seeing it as another breakthrough in artificial intelligence that could lead to subsequent breakthroughs on a range of scientific and mathematical problems. “o1 thinks for seconds, but we aim for future versions to think for hours, days, even weeks. Inference costs will be higher, but what cost would you pay for a new cancer drug? For breakthrough batteries? For a proof of the Riemann Hypothesis? AI can be more than chatbots,” OpenAI researcher Noam Brown tweeted.
But those “hours, days, even weeks” will mean more computation and “there is no doubt that the increased performance requires a lot of computation,” Husom said, along with more carbon emissions.
But Snell told me that might not be the end of the story. It’s possible that over the long term, the overall computing demands for constructing and operating large language models will remain fixed or possibly even decline.
While “the default is that as capabilities increase, demand will increase and there will be more inference,” Snell told me, “maybe we can squeeze reasoning capability into a small model ... Maybe we spend more on inference but it’s a much smaller model.”
OpenAI hints at this possibility, describing their o1-mini as “a smaller model optimized for STEM reasoning,” in contrast to other, larger models that “are pre-trained on vast datasets” and “have broad world knowledge,” which can make them “expensive and slow for real-world applications.” OpenAI is suggesting that a model can know less but think more and deliver comparable or better results to larger models — which might mean more efficient and less energy hungry large language models.
In short, thinking might use less brain power than remembering, even if you think for a very long time.
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The data center water issues are real – but they aren’t what you think.
Too often, I hear people say the number one reason they’re against data center development is water use. Heatmap’s data shows water consumption is historically the reason cited most often by activists when opposing projects. This complaint, they often say, is rooted in the fear that this nascent buildout of AI infrastructure will simply draw so much H2O it will leave little liquid left for the rest of us.
I spent weeks trying to understand how real the water use problem is when it comes to data centers, reading research and speaking to some of the world’s leading academics, large tech firms, and environmental advocates to make my best attempt at answering some of the most important questions being asked about data centers.
Before I jump into this thicket, a few caveats. I’m not going to address the host of water pollution concerns many have raised about data centers because that is for a future article. If you want me to dissect how Rep. Alexandria Ocasio-Cortez got a jar of dirty water near a Meta data center, that was poor construction practices – not a data center’s water demand. By that same token, if you're itching for me to find out how much PFAS is in data center water, I’m not delving into that here, though I’ll just say PFAS is everywhere and isn’t a data center-specific issue.
So are there problems with AI data centers’ water use? Yes. Are data centers using too much water for society to handle? It depends on what “too much” means to you. Is the AI data center boom going to usher in a new era of drought across the United States? Probably not, but there’s a few places we should be mindful of.

Researchers told me data center water use is a painfully understudied topic rendered more obscure by a lack of public information about individual H2O consumption at the project level. Those I spoke to were split on how seriously to take the topic.
Some analyses insist the sector’s water use should be regulated and tackled head-on by the sector. I spoke with Yi Ding, an assistant professor at Purdue University, who co-authored a paper laying out a framework for evaluating the water impact of computing weighted specifically for water stress. Ding told me there is currently no set of industry-led best practices for sustainable water-conscious data center operation and her work aims to fill that gap.
When I asked Ding if data centers are actually threatening individual towns’ water supplies, she didn’t hesitate: “Yes, it’s significant.”
Others in this field have the opposite view.
“Water is often brought up as the primary concern when it’s less important,” David Mytton, a sustainable computing researcher at Oxford University, told me. “The more important thing is going to be how you bring more clean energy onto the grid, and nuclear power, so that we can generate sufficient energy to build these centers.”
Large tech companies are starting to spend less time debating the extent of the problem and more bandwidth addressing the PR crisis surrounding data center and AI water use.
Ben Townsend, Google’s head of infrastructure and sustainability, told me he believes that “from a comms and PR perspective” he has “no doubt” it would be easier to build data centers without the debate over water. “Data centers operators are not explaining why they’re using water or how much water they use. There’s a complete lack of transparency or discussion.”
Google has been getting splashy around this topic, a public relations strategy that reminds me of Meta’s recent workforce training investments. Last week, Google announced five fresh “commitments” towards its “climate-conscious approach” to water use, including a pledge to “replenish more water than we consume at our sites” by 2030.
This week, Amazon made a similar declaration and claimed its operations are 75% of the way to accomplishing this goal, which it’s calling “water positive.” Brandon Oyer, director of energy and water at Amazon Web Services, told me he thinks the industry “could’ve done better” and “come out earlier” to address its water use.
“There’s just been a lot of misinformation that has led people to [be] a little bit alarmist. And rightfully so. I would get alarmed if I thought that water was going to be impacted in my community,” Oyer said.
The basics of data center water use
Data centers need water to cool large server racks whizzing away to power AI and most other internet practices, from streaming to online banking. Normally, you don’t want computers to get too hot because then they can crash causing potentially catastrophic harm to the machine.
This water use presents a number of environmental challenges. Often, server farms rely on clean, fresh water, or filtered drinking water, a need largely for functionality reasons. They’re competing for this resource at a time when supply is dwindling amidst the crisis of global warming.
Making matters worse, much of the U.S. has faced drought conditions over the past year, including states that are typically water abundant, like Virginia and Georgia, that are at the center of the data center boom. On Monday, The Guardian reported that more than half of all planned data centers in the U.S. are in “locations that have been in drought conditions throughout the past year,” citing data center site information from federal agencies and the energy data firm Cleanview.
In the top data center destination of Texas, where peak electricity demand could more than quadruple in the near future, analysis from state university researchers released in May found data centers could wind up between 3% to 9% of water demand by 2040. Projects are being developed near cities like Corpus Christi and El Paso that were already fearful their drinking water supplies would dry up before the AI infrastructure boom came to town.
“The impact of building a data center in Arizona versus Wyoming is very different,” said Ding, the Purdue University researcher. “[Companies] will say different things because of their position. The problem is substantial and sometimes it’s not that they don’t want to use water – it means they don’t have water to use.”
The most water intensive version of data center cooling is called “evaporative cooling,” which mixes water evaporation and ventilation air flow to cool rooms in ways industry compares to human sweat. Evaporative cooling uses a lot of water and regular fresh supply because, well, the water goes away once it evaporates.
One Google data center using evaporative cooling in Council Bluffs, Iowa used more than 1 billion gallons of water in 2024, a stat that made the project a poster child for perceived excesses in water use. Somewhat ironically, we know this because Google is one of the few large tech companies to voluntarily disclose direct water consumption from individual data centers on an annual basis.
But cooling tech is becoming much more water efficient. You may have heard of “closed loop cooling” – that’s when a chilling system is supposedly self-contained. These systems as designed typically rely on loops of pipes filled with coolant flowing through them. This means they should not expel much liquid. If the modern trend in data center development skewed towards closed-loop systems, it would theoretically mean very little new water supply drawn on the average day.
“If you’re using a closed loop system, the water goes into the data center and then it doesn’t really require a refill every so often. It’s a one-time thing,” Mytton said. “If you’re using evaporative cooling, the water is continuously evaporating into the atmosphere. That’s when it’s being drawn from water sources.”
Closed-loop systems aren’t perfect because of ordinary issues like leaks. These flaws have meant this innovation has done little to assuage the loudest local concerns about water use. Critics of the sector have pointed to estimates pegging a closed-loop failure rate up to 25%. But Mytton said this criticism against closed-loop cooling systems is a little misguided. “They’re just wrong. They just don’t understand how data centers work.”
Closed loop systems and water-free cooling processes (like simple air vent-based cooling) also have trade-offs, particularly the extra energy and chemicals required to make these loops work to spec. Given data center developers are often choosing gas-fired power, which also requires water and produces greenhouse gas emissions, more power for less water is hardly a comfortable trade-off from an environmental perspective.
“‘Closed-loop cooling’ is a marketing gimmick,” proclaimed anti-data center group Food and Water Watch in an April blog post, calling the practice “greenwashing” and “just clever advertising.”
We do not know right now how much water most data centers are actually using, sans a handful of companies reporting individual facility use like Google. The data center development space – Big Tech, their subsidiaries, start ups, real estate firms – is mostly keeping their individual facility water usage private, and there isn’t really any regulation at any level of government to compel this information to be released in the United States, despite it being the number one destination for data center development. Corporations often consider these figures proprietary and municipal governments often consider this confidential business information, making it likely to be redacted or withheld from public records requests.
For example, in Wisconsin, an environmental group sued the city of Racine when officials refused to give water use projections for Microsoft’s data center campus in the nearby village of Mount Pleasant, about five miles from the shores of Lake Michigan. The projections were ultimately released under court order, showing Microsoft’s data center campus was projected to use up to 234,000 gallons of water on peak days or up to 2.8 million per year; eventually those numbers could almost triple to 702,000 gallons on peak days, or almost 8.5 million gallons a year.
These projections, according to Microsoft, are for a facility where more than 90% of the facility will rely on closed-loop cooling. The rest of the data center campus “will use outside air for cooling, switching to water only on the hottest days.” The company has called this design a “technological milestone” that’ll use “roughly the amount of water a typical restaurant uses annually.”
Microsoft is accurate here: the average eatery uses roughly 250,000-to-300,000 gallons of water a year according to restaurant sustainability advocates, a level of consumption that’s led restaurants to be roughly 15 percent of total water use in commercial facilities in the United States.
Personally I think it is easier and more useful to compare a data center to a farm, especially given how many are fighting to stop these projects to preserve prime farmland. Agriculture doesn’t measure water consumption by the gallon; farms use far too much water for those stats to work here. Instead farms use acre-feet, which is calculated using the volume of water necessary to entirely cover an acre of land with one foot of water. For posterity, one acre-foot is almost 326,000 gallons of water, which is about the maximum daily water consumption of that Microsoft data center in Mount Pleasant, Wisconsin. In 2023, the average amount of water applied to a single acre of farmland for irrigation was 1.5 acre-feet, rendering this figure comparable to a large Microsoft data center. This is still a lot of water and not a 1:1 comparison, since different crops require water at different times. But even if a data center consumed that much water every day for a full year, that’s 365 days. An average large farm is a little more than 1,400 acres and many farms span far more acreage. That’s the sort of relative scale we’re working with. So, for instance, a large family farm in Stafford County, Kansas, might use something like 420 million gallons of water over roughly 1,000 irrigated acres of corn in an average year.
I’m no farming expert – there might be things about farmland irrigation I don’t necessarily understand. But it's hard for me to look at these numbers and not long for some sort of rethinking about how we’re doing water math with data centers, especially given the environmental trade-offs around using less water.
Honestly I don’t think trying to explain this math helps anymore because secrecy may have spoiled the well in Racine, pun intended. In September, a peer-reviewed study by University of Wisconsin researchers found the Mount Pleasant datacenter had become “a microcosm of a macro problem with secrecy.” The paper stated that while closed-loop systems at the Mount Pleasant facility “may significantly reduce water use during some of the year, there is still a question of transparency and why it has been so difficult to obtain clear answers about water use.” Full transparency around water use, as well as the energy required for water-lite cooling practices, would be “essential” for any future research into industry practices “to have credibility,” the study stated.
Asked for comment on the study, a Microsoft spokesperson said via email: “Our datacenter campus in Mount Pleasant leverages the latest and most innovative cooling technology available. In past datacenter designs, water has played a key role in datacenter cooling and humidification, but our new designs aim to eliminate this continuous need for municipal water for cooling. The bottom line is that this data center, and others we build in the future, will not require massive amounts of water.”
When you zoom out further, water use by sector shows that U.S. data centers are not the leading driver of water use and its scarcity to date. Thermal power (fossil energy) and agriculture are by far the largest users of water in the U.S. economy, and it would be challenging for the data center industry to ever catch up. Industry figures collected in 2015 found thermo-electric power used roughly 132.4 billion gallons of water per day. Irrigation was a close second at 118 billion gallons of water daily. By comparison, researchers have noted International Energy Agency estimates that the entire global data center sector consumed a comparable amount of water during all of 2023. These are pre-AI boom numbers, but they tell us a lot about relative scale.
However, once again, researchers, tech companies, and advocates alike all told me they believe this macro picture elides individual communities and transparency issues are rendering these comparisons unhelpful for calming concerns down. The data center conflicts are local matters felt acutely, especially in places where drinking water is either hard to come by or expensive. Your average rural desert town or midwestern farming district cares little about the world; they want to know if their own wells will run dry. As Amazon’s Oyer told me, “The hyperlocal influence you can have on a water supply is why it becomes top of mind for people.”
One way to measure data center water impacts in aggregate may be to quantify the potential infrastructure upgrades necessary to meet the industry’s demand. A new study by researchers at University of California-Riverside and CalTech found that new water infrastructure spending for data centers alone could total as much as $58 billion in only four years time. These upgrades will be necessary in order for municipal water supplies to withstand peak demand on the hottest days of the year, a need akin to grid resilience upgrades. Not to mention our nation’s sewer systems are in desperate need of upgrades.
“If a data center was able to show they weren’t stripping our water resources and convinced a community they have mitigation strategies at the local level, that’s a theoretical path,” said Kathryn Hoffman, executive director of the Minnesota Center for Environmental Advocacy. Her organization has successfully stalled data center projects in the state with lawsuits arguing city and county environmental reviews are failing to account for the full extent of local resource usage, including water.
“Unfortunately, we’re a long way from that,” Hoffman added.
And more of this week’s biggest news around project fights.
1. Matagorda County, Texas – The bipartisan data center backlash is now so powerful that a top Republican Texas state official is doing an event with the Democrat vying to replace him.
2. Albany County, New York – As we await Gov. Kathy Hochul’s decision on whether to enact the nation’s first statewide moratorium on data centers, I wanted to bring up some pretty crucial facts about the situation in the Empire State.
3. Davidson County, Tennessee – Anyone who’s anyone should be talking about Nashville.
4. Lehigh County, Pennsylvania – I’m used to eagles halting wind turbines, but now people are trying to use the birds to stop data centers.
5. Laramie County, Wyoming – We had another anti-wind rally backed by national conservatives, this time in Wyoming.
6. Ellis County, Kansas – Let’s end on a sweet note: a giant solar farm getting its permits.
A conversation with Craig Lawrence of Energy Transition Ventures
This week’s conversation is one of my favorites so far – Craig Lawrence of Energy Transition Ventures. Lawrence has been around the block and back again when it comes to the cleantech investment landscape. So I took note when he got into a brief back-and-forth with an activist fighting data centers in Indiana who claimed there were “so many clean energy people who no longer care about climate change” because they “now support fossil fuel data centers if some nominal amount is met with clean energy.”
Lawrence replied, “Some of us are simply realists.”
It was a provocative answer. I reached out to Lawrence and asked if he’d explain what realism on cleantech and climate change looks like in the age of the data center boom. The following conversation was lightly edited for clarity.
So okay, what does “realism” in the clean energy space look like in the era of the data center boom?
In general, it looks like progress. Whether that’s technological or social, which often includes increased energy consumption. This is an extreme example of demand appearing at once. And what’s been incredible for me over 25 years of being involved in this stuff is, we’re finally at a point where clean energy can meet most of this demand – the cost of renewables and the cost of energy storage are now at a point where they directly compete with or without subsidies against fossil fuels.
However we’re not at a point where it's reasonable to expect 100% of this demand can be renewables. I don’t think that’s practical. Natural gas is still a very affordable, very flexible energy source. The data centers are going to use them.
I think the game should be figuring out how to support the most clean energy. That includes nuclear and other low-carbon sources to meet this demand.
I’d like to represent the other side of this really quickly. The pro-moratoria side here would be, why? Why do we actually have to build all of this? Why not just halt these data centers so the gas isn’t built, then invest in renewable energy to green our grid?
I made that comment about being a realist. We have an administration in this country that isn’t going to do that. Who will halt that? Who is in a position to actually do that? The answer is nobody.
We have another problem to worry about – the administration halting renewable energy projects. We have to prevent that from happening. I’ve been following the school of thought that there’s a grand bargain on permitting reform applying to renewables and other sources of energy.
I honestly truly believe that head to head, renewables and energy storage beat natural gas. In the free market of power, as much as it is a free market, renewables are winning and so you are painting a target on your back trying to stop all development unless it’s 100% renewables. You’re going to face a backlash from that.
In the U.S., 93% of new electricity generation is solar, wind, and storage. Do you really need 100%? You’d like it to be but man, take the W.
We’re winning. Not only are we winning but we are destroying the competition. To create a battle that has the potential to create significant backlash against renewables is the wrong move right now.
Okay, but on the opposing side someone would say that argument is what landed us in this place to begin with. Some would say a frame of realism is why we can’t seem to shake a reliance on fossil fuels.
I don’t think that’s the reason why.
Once renewables and storage became cost competitive they’ve dominated since. Prior to that, they weren’t cost competitive and it was a policy fight to say people should be forced to buy more expensive electricity that was cleaner for the climate. That battle was difficult and had some wins and some losses. We’re past that battle now.
Renewables are winning in the global market. Would I love a scenario where we could meet all the demand with solar, wind, and batteries? Yes. And I think we can get there, but there are real practical limitations to those resources too. They’re not 24/7 resources, even though they’re getting close to that.
Let’s just say I agreed with them and that side of the argument. What can you do about it with this administration? You can certainly try to elect candidates that’ll be supportive of it. You can’t force a moratorium.
Luckily, for that side of the argument, there’s plenty of people upset about data centers that aren’t just thinking about climate change.
How do you feel about the data center backlash as an investor in cleantech, and does it impact the decisions you make around who you potentially finance?
Not yet. The data center boom for us is indicative of a broader boom for increased electricity demand, which is generally good for what we invest in.
I think this feels very deja vu. Whether it's nuclear or renewables or pipelines, someone is going to be against it and make a lot of noise. That’s part of the reason we struggle to build things in this country.
But no, if anything, the whole AI and data center buildout is a tailwind for the energy transition and climate technologies. It’s helping gas too, no doubt, because people are trying to procure any power they can, and so they’ll do it by whatever means necessary, but I continue to think we’re oversupplied globally on solar panels and batteries. That’s thanks to China, primarily. And you can build those facilities in one or two years. Gas has five-plus lead times for turbines. We’re in a position to win that battle without having to make it a political battle over halting the buildout of these things.
Do you think the upset over data centers will impact the energy projects to power them?
Yes, I do. I’m seeing subsections of X, farmers and people purporting to support them, that are really upset about solar on farmland and engaged in interesting discussions around it. The same happens with data centers and farmland. It’s interesting to try and figure out their motivations. Is it preserving the farming or an angle to attack development they don’t like?
I am seeing a mobilization of people against buying up land and buying up electricity and water and using it for… xyz. Right now the flavor is data centers. It’ll be something else down the road. We’ve even heard the same things around the EV charging buildout.