📈 44 cm water level rise under the IPCC business as usual scenario. This number shows that climate change is very real for Singaporeans and for their data centers, close to 10% of the whole of APAC! 
🎧In episode 36, Gaël Duez discussed with Professor PS Lee, National University of Singapore Dean's Chair of Mechanical Engineering and one of the top experts worldwide on data center cooling, the challenges in making data centers sustainable. 🔍Some key points of their exchange are: 🌡️why temperature rise has multiple downside  🌡️energy challenges that affects the sustainability of data centers 🌡️liquid cooling technology as an important option 🌡️why lessons from DC operating in tropical climate apply almost everywhere And much more!
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Poh Seng's sources and other references mentioned in this episode:




Transcript


Gaël Duez 00:21
Hello everyone. Welcome to Green IO with Gaël Duez. That's me. Green IO is a podcast for responsible technologists building a greener digital world one byte at a time, twice a month on a Tuesday. All guests from across the globe share insights, tools and alternative approaches enabling people within the tech sector and beyond to boost digital sustainability. Because accessible and transparent information is in the DNA of Green IO, all the references mentioned in this episode, as well as the transcript will be in the show notes both on your podcast platform and on our website greenio.tech when it comes to sustainability, I have a sweet spot for Singapore because of its uniqueness. This is one of the top cities in the entire world which has benefited the most from the global extractivist, highly carbonized and financialized economy, and also one of its most at risk of climate change. Hence a blossoming of initiatives there on how to both pivot towards more sustainability and mitigate climate change impacts. And these efforts apply especially to the backbone of its infrastructure data centers. As we are growing aware that the human body has some physiological limits that can be reached during heat waves where the wrong mix of high temperature and humidity is reached. It's death for people staying outside too long and this concerns everyone, not only the populations usually at risk like infants or elderly people. It was really well illustrated by Jancovici Jean-Marc and Blain Christophe in their international bestseller comics World Without End and based on a 2020 mega study published in Environmental Sciences, a third of humankind is now at risk to live in places where temperature could be lethal several weeks per year. Well, everything that I just said about humans applies to data center equipment which also needs to be cooled down 24/7 for many obvious reasons. Starting with latency and sovereignty, we cannot move all data centers in the world where the air will remain cool like the Nordics. Hence a serious challenge for the tech industry, how to run a sustainable data center and more specifically how to build sustainable data center hubs where tropical climate creates hurdles which are getting bigger due to climate change. To discuss this, I'm honored to have Professor P. S. Lee on the show. Based in Singapore, PS is National University of Singapore Dean's Chair of Mechanical Engineering and one of the most cited scientists in mechanical engineering and transport energy rings worldwide. He has specialized in data center engineering for two decades and he is also a field practitioner. The founder of Coolers DC, what a cool name, which advises top DC operators like Equinix or Meta. He will also be our keynote speaker at the Green IO Singapore Conference in two weeks, April 18 to be precise. One reason among many reasons to join the first conference in Asia focusing 100% on green it and Green IO. Listeners can get free tickets using the Voucher GREENIOVIP and how exciting it is to kickstart my discussion with Professor Lee. Welcome, Poh Seng. Thanks a lot for joining Green IO today.
PS Lee 03:54
Hi guys, thanks for having me. So it's my pleasure to be on your podcast.
Gaël Duez 03:59
So PS, I played again with the excellent Climate Central's coastal risk screening tool, which enables people to simulate the impact of a sea level rise, among other impacts. And the results were already concerning for a 44 cm water level rise, which is the current IPCC best estimator for the business as usual scenario with most of the iconic gardens by the bay in Singapore under the water. And if we simulate a 2 meters rise, a likely scenario. If some tipping points with ice in Greenland or Antarctica are reached, well, the entire Singapore's harbor is at risk. My point is, climate change is very real for Singaporeans. Could you maybe explain to us why and what is more precisely at stake here?
PS Lee 04:53
Sure. I would like to refer to the recently published 2023 Singapore Climate Reports, which marks an alarming continuation of global warming trends, with Singapore experiencing its fourth warmest year since unprecedented temperatures, especially during the months of May and October. This underlined the urgency of addressing climate change. The report's projection of up to 326 high heat stress days by 2099 in high emission scenarios starkly highlights the impending challenges, especially for industries like the IT sector.
Gaël Duez 05:33
Correct me if I'm wrong, but Singapore is a very massive IT hub in Southeast Asia, is that correct?
PS Lee 05:42
Yes. As of two to three years ago, in Singapore, the total data center capacity is actually close to 1, that is close to the 10% of the whole of APAC. So for city states to be hosting that kind of capacity is actually quite amazing, but it's actually important to manage the power and the associated carbon footprint. So it is. Right now, the data center industry is already consuming 7% of Singapore total electricity consumption. And if we don't manage this in a couple of years, this can actually go up to 12%. So that's why the Singapore government has actually imposed a data center moratorium about two and a half to three years ago, which they finally left the year before. Thereafter, there was a data center call for application, which the industry expected to meet very stringent criteria, including PUE, no more than 1.3, as well as the adoption of innovative and sustainable data center solutions.
Gaël Duez 06:59
You mean that for two years and a half it was not permitted to build new data center facilities in Singapore.
PS Lee 07:07
That's right.
Gaël Duez 07:08
And just to make sure I understood well it's already 7% of electricity consumption and it could triple with the current trend.
PS Lee 07:17
Yes and especially with the interest in AI in other high power workloads. So if we don't manage this in a sustainable fashion, this percentage is certainly going to increase very sharply over the next couple of years.
Gaël Duez 07:35
So clearly the Singaporean government doesn't want to go the Irish way with the Irish scenario. Where I recall today the electricity consumed by the data center industry is already above 20% if not 25%. I don't recall the number exactly but it was really mind blowing. And so you were mentioning this very strict criteria to build a data center in Singapore, obviously low carbon electricity and also innovative solutions. Maybe it would be interesting to unpack the challenges that data center operators in Singapore and more largely in tropical climates are facing.
PS Lee 08:19
Yeah sure. I think the first and foremost operating data centers here in the tropics with a high ambient temperature and humidity is actually going to be a very energy sapping exercise because of the constant cooling needs in order to maintain the IT equipment within acceptable temperature range in order to ensure proper and reliable operations. But associated with the heat stress that we're experiencing during the recent few years due to climate change, this has actually imposed a more challenging condition for data center operators to ensure the resilience as well as efficient operation of data center here in the tropics and specifically here in Singapore. So that's definitely going to be they are constantly looking for more energy efficient cooling solution and this goes beyond operational efficiency, rethinking energy sourcing as well and potentially integrating renewable energy sources to mitigate the carbon footprint. And for city state like Singapore in terms of domestic generation of renewable energy is going to be limited as well. I think the only viable renewable energy source here is actually solar and based on a report published by the Solar Energy Research Institute of Singapore series which is hosted here at NUS. So even if we were to sort of use all our rooftop space for the solar panels, so the percentage of the electric supply that comes from solar is actually still going to be very limited, well less than 10%. So that's why I think Singapore is actually adopting innovative approaches whereby we're actually cutting agreements with our Asian neighbors to look into the imports of green electrons, low carbon electricity. Then I think related to the temperature challenge or the temperature or what we call a thermal management challenge associated with operating data center here, there's also this wear and tear on it equipment because the increased heat stress days will directly translate to accelerated depreciation of critical data center equipment. And this necessitates more effective maintenance and proactive design consideration that can withstand the rigor of a harsher climate, and again, related to a climate. So when it comes to heat rejection, typically we need to operate the cooling towers that actually consume water, then that brings about the water sustainability issues. So given the intensity or the intensification of the extreme weather events. So water cooling, the technologies, while efficient, may actually impose a sustainability challenge. Hence, we are always actually looking at better ways of reusing water recycling along with explorations of air and more efficient liquid cooling alternatives. And these are now becoming imperative. But we are also grabbing with, for example, the challenge of a skilled workforce, especially if you look across the region, Southeast Asia. So the data centers industry is actually booming. So how do we actually adapt and mitigate the impacts of climate change? Data center also means nurturing a workforce which is proficient in engineering and understanding sustainability practices and technology. So there are definitely quite a few challenges that we are confronting today in order to ensure the sustainable growth of the IT industry.
Gaël Duez 12:42
If I follow you here, in trying to wrap up what you say, I've listed four challenges. You've got the energy challenge, the equipment challenge, the water challenge, and I would say the workforce challenge.
PS Lee 12:56
Yes. These are the exact four points that.
Gaël Duez 12:59
I mentioned, and I think it will be worse deep diving on all of them. So if we start with the energy challenge, I've got a first question. So you mentioned solar, and solar not being able to attend more than to contribute to more than 10% of the overall electricity production. But what about wind energy? Is there any ability to put wind from around Singapore or is it just something completely nuts because of all the boat traffic?
PS Lee 13:33
Yeah. So Singapore is what we call a renewable energy challenge country, right? So when it comes to the wind, unfortunately, our wind speed is actually on the low side. If you were to put in the wind turbines, whatnot, right. In terms of the energy that this can generate will be very limited, right. Because of the low wind speed. Hence comparing the different options, solar is actually the only viable renewable energy option. Although in the recent one, two years, there have been a lot of interest in assessing the potential for geothermal. And there's also talk about going into nuclear, although I think the nuclear question has not been fully addressed because we are in CD states. So certainly the public perceptions, the safety related issues will have to be adequately addressed before Singapore to take a position. So we are very much constrained in terms of renewable energy options.
Gaël Duez 14:47
I think I'm not 100% sure that regarding this energy innovative approach you mentioned, which is basically outsourcing the production of low carbon electricity, I think you're the one who mentioned it as a geopolitical problem. Could you elaborate a bit on what are the pros and cons of sourcing your low carbon energy elsewhere than on your own territory?
PS Lee 15:13
So sourcing, renewable, the energy or the low carbon electricity from for example our neighbors. So that actually requires the cutting of bilateral agreements. And if let's suppose the electricity is actually to pass through in more than one country, then that actually requires multilateral agreement. Hence the political issues will then come into the picture. But I think Singapore has been actually very forward looking and over the past year or so, in fact we have signed an agreement totaling more than four gigawatts of clean electricity imports. But obviously the data was in the details. For example, what will be the price that would be paying for such clean electricity? The imports, because our other neighbors also have their net zero commitments. So there are actually a lot of issues. But the one thing is clear, I think once the Singapore government decides on the course of action, they will actually put in all the necessary efforts to realize them. So I feel hopeful that it will be a win-win arrangement. For example, we will collaborate deeply with our asean neighbor so as to sort of increase the deployment of renewable energy projects so that when they have access they can actually look into exporting some of these clean electricity to Singapore. But it may actually require some sort of differential pricing. For example, maybe for their domestic demand the rate will be kept at the lower level, but for those that they are exporting to Singapore, that may actually incur a certain premium.
Gaël Duez 17:10
What about the infrastructure? I mean, you need a connection cable. Are they already there? Do you plan to construct more?
PS Lee 17:16
Yes, I think the associated grid infrastructure will be actually critical when we look at linking up the grid that cuts across different countries. For one, I think there may be differences in terms of some of the standards. I think this is something that Singapore will have to work with the neighbors to finance the grid infrastructure and that may actually require quite a big amount of upgrading or the expansion of the existing grid. So I think this will likely be a costly exercise. But I think if this will actually be a win-win arrangement, by adopting a collaborative approach, we can actually increase the renewable generation capacity.
Gaël Duez 18:05
And if I run a data center facility in Singapore, how does it work concretely for me? Is it more okay, my government is in charge of decarbonizing the electricity, so I consume the electricity that I've got in the grid. That's it, period. Or do they also have to close a deal like purchasing power agreement or some sort of directly with foreign countries?
PS Lee 18:32
So I think this is the part that is still not quite clear yet. So for example, can you achieve the data center operators, can they cut a direct view, for example, power purchase agreement with renewable generation plants, for example, in Indonesia? So this is the part that is still not quite clear because the agreement that has been cut is still country to country. But I think there's actually a lot of interest from the data center operators to have access to as much green electrons as possible. But the details have not been ironed out yet. But I suppose it will be done in a phase approach. First, country to country, the agreement has to be done then that can actually trigger down to the various sectors. Certainly. I think data centers are one industry that has strong demand for the low carbon electricity. But there are also other sectors, right? So I think the Singapore government will then have to figure out a way. Then when they import such, the green electrons, which sector should it go to? Is it the data center industry or is it the semiconductor industry? Or would they actually allow, for example, the sector to actually cut direct agreement with the renewable, the generation, the plan overseas? So this is not clear yet. So I suppose over the next two to three years, right. There will be actually more clarity. But I think what is clear, Singapore government has always actually had a very consultative approach. So I'm sure they will be actually reaching out to industry, including data centers, to have the dialogue and to sort of come up with a framework, right, such that it will actually benefit, for example, data center operators who have the desire to steeply decarbonize their data center operations.
Gaël Duez 20:41
And eventually, because I believe the Singaporean electricity grid is fully unified, it's a theoretical question, or at least it's a bit like an analytical accounting question, because an electron is an electron. It's not green or per se, but it's more like between the different business interests, which business interests can claim, between the semiconductor industry, building and heating and or heating, not that much, but cooling. And in the data center industry, which industry will contribute the most to the low carbon electricity sourcing effort? But still. So how many data centers and how many operators are we talking about? Is it a very concentrated market with a handful of firms running larger facilities, or do you still have a lot of smaller or medium sized data centers run by, you know, I don't know, institutions, big companies, etc.
PS Lee 21:40
I think it's a mixed bag. So for Singapore, the data center industry, it has been reported that there are between 70 to 80 data centers operating here in Singapore. So you look at some of the more recent announcements, in particular, meta -150 mw, obviously it's huge, then, even since they actually consolidated some of the data centers. So they are actually probably in the range of 70 to 80 megawatt. So again, very sizable. And I think there's also the Google, the Microsoft, but certainly there are also the smaller data centers. That's probably in the range of maybe between 10 to 20 megawatt. But I think moving forward, for a mature market like Singapore. We will have to look at the edge data centers, which are smaller in capacity. Maybe we should be actually looking at anywhere between five to ten to 20 maximum in the capacity. And for those data centers, they are handling very high power workloads. For example, if you are doing AI training, I think it makes more sense to actually have this in, for example, Malaysia, in Indonesia, because they have abundance of renewable energy potential, they can then obviously have the green electrons to offset the carbon footprint associated with the very high capacity data centers. So I'm actually very hopeful that the various parties, various countries come together to set up what I call the sustainable data network, whereby we actually work in a very collaborative fashion so as to more effectively manage the carbon footprint of the entire Southeast Asia region.
Gaël Duez 23:40
Because you're an expert on these topics, whether my electricity is low carbon or not, I think the question of reducing the electricity bill is pivotal here. I would like to ask two questions that are very closely interlinked, as far as I know. How should we build data centers today, or refurbish them, and how should we run them to make sure that we save or we reduce as much as possible, or energy consumption.
PS Lee 24:14
I think certainly you make an excellent point. There's this constant desire to have access to more green electrons. I think this has to be peltrapped with energy, the efficient technologies specifically addressing the high energy, the consumption associated with operating cooling systems for data center, suddenly we can actually look at innovative cooling technologies, for example, the exploration or the adoption of single and two phase directorship and immersion cooling systems. So these are actually at the forefront of reducing the data center energy use and improving the cooling efficiency. And there's actually another wonderful side benefit that is less reported associated with the use of high efficiency, the liquid cooling that actually allows your hardware to actually operate at optimal efficiency. So, meaning that you'll be able to get the optimal workload accomplished versus, for example, when you are operating your IT equipment under the air cooling mode, which often goes into suggestion like thermal throttling, meaning that you're not able to fully maximize in terms of the performance. So I think adoption of innovative cooling technologies is certainly one of the first things that we want to do in terms of improving the energy efficiency of data center operations.
Gaël Duez 25:58
Just regarding this water cooling approach, I've got a question, which is how sustainable it is. And my question comes with two faces, and we will talk about the water consumption later. The first, is it mature enough or is it still R & D? Because last time I checked, the moment you put metals in water, bad things happen, corrosion and so on. And that will be my very minimalistic contribution in terms of chemistry. But how much is it like R and D and a bit of hype, or how sustainable it is? And my second question is how big the investment, environmentally speaking. But it also comes with a financial cost, obviously, when you refactor or you refurbish your factory to enable water cooling, because you could have a lot of carbon embodied with the data center facility itself. So hence my two questions, which are two sides of the same coin regarding the sustainability of water cooling technology.
PS Lee 26:59
So liquid cooling is not new. It has actually been around for a decade. It's just that the data center, being a recent adverse industry, didn't quite adopt it in a big way. But I think we are actually getting to a stage whereby, because of the increase in thermal design power, because of the sustainability imperative, I think we are getting to this stage whereby liquid cooling really needs to be a serious option. And it's certainly well beyond R & D. So to give an example, we actually started a company called CoolDC. We started off with a test bedding at one of the major co-location operators in one of their production data halls. And shortly after the completion of the test vetting, we actually managed to secure a project with a major local bank. And they are actually looking at implementing liquid cooling for 16 racks and this handling production workload. So certainly I think it's actually ready for the big time. But the challenge is actually how do you come up with a system that can scale with demand, when talking about, for example, high power IT equipment, it will not happen overnight, there will be a scaling up over time. So then the challenge is actually how do we configure a cooling system that can scale with demand in a very cost effective fashion, in a fashion that minimizes the disruption to ongoing operations. So I think there are actually ways to do it, because without liquid cooling, in fact there are actually different configurations. It can be air assisted, liquid cooling, which can be pronged into an existing brown fuel air cooled data centers without laying the elaborate piping network. But then obviously, going back to your second question, then what about the impact in terms of the environmental impact, for example, in terms of embodied carbon, so should you, for example, I have to set up new data centers. So again, I think it really depends, right? So we're very innovative in design. In fact, you can retrofit, right? Brownfield Data Centers to be very energy efficient. And that major local bank, the client that I mentioned just now, is actually in fact retrofitting one of their existing data halls. So as to support the equivalent  that can be done. It's just that the engagement, the dialogue with the infrastructure folks and the IT team has to happen at an early stage. So as to minimize the disruption because if after talk, then obviously that will potentially lead to the interruption to the IT operation, but then if, for example, you start the dialogue early, you know, when the IT team is planning to have the next round of hardware refresh, it refresh. If you time the upgrading or the retrofitting of the infrastructure to support liquid cooling in line with your IT refresh cycle. I think that can be done with very minimal disruption. And the other initiative that I have been spearheading, the sustainable tropical data center. In fact, what we did is actually we retrofitted a 40 plus year old power substation into a very efficient data center. That's where, so moving forward, that likely will be the model. Because for one, you want to save on embodied carbon. And the fact that for a mature market like Singapore, we are actually running short of power. We are also running short of space. We can't keep continuing to have new build data centers. But the fact that you see we have a lot of existing building stock, I think there's one perception that liquid cooling may actually lead to increased water consumption. That's not really the case because in fact, when talking about direct to chip or emergent cooling, this can be fully the closed system. For example, instead of rejecting the heat through a conventional cooling tower, which is obviously going to consume water, you can actually perform the heat rejection using a dry cooler. In fact, we have actually demonstrated this at that cold location data center that I mentioned. We actually demonstrated that you can actually simply reject the heat using a dry cooler without consuming the water. So again, really there's a lot of variance in terms of how you configure a liquid cooling system. So I think it really needs to be a very early engagement between the infrastructure team, the IT team, as well as the solution provider, so that you can actually come up with a configuration, a solution that is really fit for purpose because you don't want to over design or under design. Then we need to adopt a holistic approach whereby we actually factor in what's the impact in terms of the embodied carbon, what's the impact in terms of the water consumption. Then obviously, what's the impact in terms of the power or the energy consumption, which is typically measured in terms of power. But moving forward, I think it has to be really a very collaborative approach, and the dialogue needs to actually start as early as possible and not as an afterthought.
Gaël Duez 32:49
I've got a question for you regarding what you said about water consumption, which was one of the four challenges that you've listed. Where do these big headlines about water consumption of main hyperscalers, at least western ones, come from if water cooling doesn't consume that much water? Because, you know, I mean, all of them, Google, Azure, AWS, they've been blamed for consuming a lot of water. So where is the issue here? Because you tell us that, well, it doesn't, you can run a closed system and it doesn't consume water, or at least marginally so can you enlighten us a bit here?
PS Lee 33:32
One option, as I mentioned just now, is actually to use, for example, a dry cooler instead of cooling the tower, thereby having a fully closed system without actually consuming water. But then obviously there's a trade off, right? So if you operate a dry cooler versus a cooling tower in terms of the PUE, in terms of efficiency, right? The former, without the consuming water, will be actually less efficient, somewhat less efficient then in terms of the footprint. So the space required for a dry cooler versus cooling tower is actually going to be bigger. So I think it really has to be a holistic assessment. So what makes sense? Do you want to go, for example, the best possible PUE, or do you want to have a more balanced so called matrix involving not only the PUE but also the weight? So I think that's probably what's necessary moving forward. So for data center operators, including hyperscalers, to look at things in a more holistic fashion. But then I think the fact is still hyperscalers actually have very high capacity data centers. So then that obviously will translate to a large carbon footprint. Yeah. So I think that's something actually unavoidable in certain sense, but I think as much as possible we will have to then maybe look into the transition from air cooling to cooling because that will bring about a reduction in terms of the total energy consumption. So I think that's something that we do, but I think the other aspect that can be done is actually the end user. So we also need to be probably more prudent in terms of our consumption of digital services. So maybe you want to limit how much TikTok or YouTube that you watch each day.
Gaël Duez 35:27
It's a bit like the elephant in the room. Is sobriety like digital sobriety a topic at all in Singapore or in Southeast Asia, as far as you can tell?
PS Lee 35:37
I think people, obviously so here in the news, in social media, that we need to be more sustainable. Carbon emission is definitely going to be something challenging to manage, but it's just that I think some of the things that don't actually trigger down to the individual, to the personal level. So moving forward, we may really need to consider imposing a personal carbon budget so that you're more conscious in terms of how much digital services that you consume. I think it's all part of being a responsible citizen. Everyone obviously is conscious of climate change. We really need to take it upon ourselves so that we are also very conscious in terms of managing our consumption. I think that certainly will be very complimentary to all the wonderful energy efficient technologies that we are deploying in our data centers. Very complementary to the integration of renewable energy. But if, let's suppose we can in tandem manage the consumption while actually managing in terms of the energy efficiency improvement, integration, and renewable energy, I think all in all, that will make the earth more sustainable.
Gaël Duez 37:13
The example you gave about making people more aware of the need to refrain from digital consumption, I think it connects pretty well with what you've said several times before that. Dialogue is key. And making sure that all stakeholders start discussing on how to make the data center industry more sustainable. And my question is that a Singapore way of doing things like, it seems to be pretty much in the DNA of Singapore business and governments to talk to each other. I don't know if it includes consumers as well as you've just mentioned right now, and how much of the government is involved and how much more specifically does it use the stick or the carrot.
PS Lee 38:07
So I can frame it as dialogue and collaboration. So I think Singapore has always been very collaborative. I think one, the key reason being that Singapore is actually a migrant society. We have a very relatively short history. So in our 50 years of nation building, I think Singapore achieved a lot. And I think that happened because we are able to rally people coming from a different background, different races, different religions to come together in a very collaborative fashion, then obviously you see collaboration between government, industry, academia, civil society. So I think that really is very much needed when we want to actually address the multifaceted challenges associated with sustainability, associated with climate change. I think the Sierra Leone government probably will soften, or rather usually will first go with the carrot before they bring the stick. I think really helping the industry, helping the public to see the needs to be more sustainable and the need to be more collaborative, I think that will be actually more effective than, for example, imposing the very draconian measures. I'm still hopeful that Singapore will be able to focus more on inculcating or enculturation. They need to be sustainable, they need to be collaborative so that people come together willingly. Because I think that will be more effective than forcing people to comply with certain regulations. I thought that should be probably the last resort but I suppose it needs to be a balance, because obviously there will still be companies that are non compliant. Certain amounts of regulatory advancement will still be necessary.
Gaël Duez 40:20
And I'm asking you also the question, because I'm pretty sure you're familiar with what is going on in the rest of the world and in Europe. Very recently, an energy efficiency directive has been launched and it was pretty precise regarding the metrics that a data center should now report above a certain capacity. And it goes way beyond just renewable energy and PUE or we also waste use, etc. Do we have this kind of reporting requirements planned in Singapore, in other areas in Southeast Asia, for instance, or nothing to your knowledge?
PS Lee 41:02
Not to my knowledge, but at some point we may have to do the same thing. Going back to our earlier discussion that moving forward for Singapore especially, we will need to be very selective in terms of the kind of data center, the kind of workload that we are hosting. Obviously, we are very energy constrained. We have very limited options when it comes to renewable energy sources. So I think at some point we will probably need to mandate that the data center operators will actually need to report various matrixes, for example, maybe pertaining to PUE or WUE, what's the amount of renewable energy, the sources that are integrating into their operations, things like that. But I think it will take a while. I think at least for now, I see Singapore, the government actually engaging industry, encouraging them to go through the green transition. And I think that is something that will take some time. But I'm sure the Sambo government actually provides the necessary support, for example, in terms of grants, in terms of assistance, in terms of technology, so that the existing stock of brownfield data centers, especially those that are quite dated, right, can then go through this green transition.
Gaël Duez 42:36
Now I'd like to zoom out a bit and talk about resiliency and the lessons for the rest of the world, because tropical, or you meet subtropical climates, are pretty widespread around the globe. And for example, in the state of Virginia, home of AWS, this is a subtract tropical climate. And I don't know Pierce if you read it, but in 2022, the reviewer, security technology published a fictional story about a heat dome descending in the summer of 2025. So it's next year near the town of Ashburn, Virginia. Ashburn is called ‘data center alley’ by its folks in the US, because it's by far the largest concentration of data centers, not just in the United States, but in the entire world. And spoiler alert, it ends with a data center manager having to shut down an entire hyper scaler facility facing the cornelian choice of either losing billions of dollars in equipment or entering its history with the first ever cloud blackout. And everything you said in this interview makes this story some sort of more likely because you describe the worsening climate condition that Singapore faces, all the challenges to cool down data centers, etcetera. And my question is: how realistic it is, and what are the lessons for pretty much everyone running a data center facility in the world from the specific conditions that operators in subtropical areas, the one who are the most at risk of heatwave? Well, what could be these lessons? 
PS Lee 44:30
I think certainly the increasing episode of heatwave is going to pose challenges to the data center industry, especially if they are still using conventional air cooling systems. So I think this is part of that kind of dovetails here very nicely into why I think liquid cooling is actually the way to go because one of the studies that we did, which I thought is pretty interesting. So what we did is actually we increased the supply air temperature as well as the supplied liquid temperature, because we actually have two racks, one which is actually an air cool rack, the other is actually the liquid cool rack, both having the exact same IT configuration. So the only difference is actually the cooling method. So what we have shown is actually for the air cooled rack, the server's performance, the energy consumption, it's actually very strong functions of temperature, because when you're operating your IT equipment using air cooling, all your chip temperature, or what we call junction temperature, are actually much higher, typically in the range of 80 or 90 degrees celsius. And that is actually very close to the temperature threshold, because you want to protect the electronics, [for] the server you usually set the upper temperature limit. So once you cross that limit, then the thermal throttling skips in because you want to protect your electronics. But when you actually operate your liquid cool rack, even with an increase in supply temperature, what we notice actually both the performance as well as the energy consumption actually stays relatively insensitive to temperature. So the implication is actually what if you have a liquid cooling system, or rather if you are using a liquid cooling system, even if, for example, there's actually an increase in your outdoor temperature, ambient temperature, whatnot, that's not going to lead to a big issue in terms of the performance of your IT equipment in terms of the energy consumption by the demand. But if you were to actually use the conventional air cooling, then you'll run into serious problems because of the increase in your ambient temperature that actually leads to your ip, the hardware going into more frequent thermal throttling, which is obviously going to affect the performance. That's also going to mean that your equipment now is going to have a higher power penalty. So I think from the resilience standpoint, I think it makes a lot of sense for the industry to actually look into transitioning from air to liquid cooling. So that's actually my personal experience that I can share when it comes to the data center resiliency from the angle of cooling.
Gaël Duez 47:48
However, you mentioned earlier that transitioning a full entire facility from air cooling to water cooling comes at a price, and you were advocating more for a modular approach. So if, how much would it cost for a per scaler to migrate entirely air cooling to water cooling? I think it will be ace watering without bad word play.
PS Lee 48:15
It's true. If you have software looking at retrofitting and air cooled data centers to liquid cool, and suddenly there will be the additional CapEx. The fact that you have a sunken investment on your air cooling infrastructure and for you to replace that with liquid cooling infrastructure, certainly there will be additional CapEx, but it may, you may have no choice, right? If let's suppose your tenants come to you and say, I'm going to bring in one rack of GPU service because I'm going to run generative AI workload. If you don't have the supporting liquid cooling infrastructure, there's no way that your tenants can actually operate his high power servers or his high power rack. Even if they can operate it, they wouldn't be able to get the performance that they paid for. So the multiple factors that you need to consider one is actually, what's the cost, what's the ROI the other is actually what is the business opportunity that you don't do it. Because if you can't support the high power rack, high power equipment, your tenants will take the business and go to your competitors. So I think it really requires a holistic assessment. Certainly ROI is important, but at the same time, do you want to future proof your data centers so that you're able to handle the current, the future workload that's going to come into your data centers? So I think operators probably don't really have too many options. If you don't do it, you are going to fall behind your competitors.
Gaël Duez 50:05
So when economics incentives meet sustainability incentives, I think that's a nice way to wrap up the entire episode. Professor, before we leave this episode, I've got one final question. Would you like to share a positive piece of news with us? Whether it comes to sustainability in general or more specifically, its sustainability?
PS Lee 50:32
Sure. Traditionally, the Southeast Asia data center markets are not known to be trailblazers in terms of adoption of the most advanced, most innovative solution. But because of the confluence of various factors, including the increase in thermal design power achieved because of the sustainability imperative. So over the last 12 to 24 months, we have been seeing a lot of interesting developments. For example, data center markets in Malaysia and Indonesia are starting to sort of call for liquid cooling infrastructure. So I think that can propel the region, in fact, to be the leaders when it comes to adoption of sustainable and innovative data center solutions. So I'm actually very hopeful that the region can achieve leadership in terms of embracing the most sustainable and the most innovative solution. But going back to one of the key discussion points, it has to be a highly collaborative approach.
Gaël Duez 51:42
Yeah, that was the key word here, collaboration. And we've got a lot to learn from a small but very powerful state who has to work well with all its neighbors and to source electricity and to find innovative solutions. Thanks a lot. PS, that was lovely to have you on the show. I'm eager to see you on stage for Green IO Singapore. I hope that many listeners based in Singapore and maybe some of them based in Southeast Asia will come as well. Thanks a lot again and talk to you very soon.
PS Lee 52:16
Sure. Thanks for having me.
Gaël Duez 52:19
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