At Verne Global Finland’s The Air datacentre in Helsinki, excessive heat from hot air returned from server air cooling is transferred to water via heat exchangers before being approved by the district heating company.
The water is therefore primed from a temperature of about 30 degrees Celsius using heat pumps, according to Kim Gunnelius, managing director of Verni Global Finland. ” The expected temperature varies depending on the outdoor temperature, but it’s usually high—over 90°C or even on cold days.
The datacentre generates 1.3 MW of heat for every m2 of IT power, or power supplied to the servers, with heat pumps adding 300kW of more electricity to raise the temperature from 25 to 30 degrees Celsius to roughly90°C. According to Gunnelius, heat pumps can also be used to convert energy into heat, with the system enduring energy losses of only a few percent.
In Finland, obtaining permission for the project was” straightforward,” he continues, with the district heating company that was involved locally being “very positive and proactive,” not least in reviewing it and providing input on plans.
He acknowledges, however, that this meant they were n’t reliant on a one business or application because they had access to an all-encompassing city-wide service with continuous energy demand.” The fact that there was already an in-place district heating network, letting you plug into an utility, made it much easier.”
Given that it was also directly outside the Verne Global plot, the existing pipe was easy to plug into. According to Gunnelius, you might require specialized point services in various locations in order to integrate the datacenter with an industrial process and take advantage of the excessive heat.
However, he cautions that these projects are not always financially worthwhile, such as when electricity costs are high. He claims that although there were some subsidies accessible in our case, heat reuse is currently one way to get to a lower power tax class. Some nations that require heat reuse lack the necessary infrastructure to plug in, which can be problematic. The same is true for Finland’s some smaller towns and rural areas.
energy costs
Power price fluctuations brought on by the energy crisis of 2022 could not often be completely offset by buying fixed-rate electricity. The essential temperature in the district-heat network also depends on the inside temperature.
He adds that district heat pricing is fixed on a monthly basis, which presents issues if the project business case depends on selling heat.” We have introduced automation for monitoring the electricity pricing, as well as the temperature requirement for the heat required from the utility.”
Verne Global anticipates switching its highest density installations to liquid cooling in response to incoming customer requests. This will allow the cooling system to operate at higher temperatures, use less power, and increase efficiency, achieving 1MW of IT power plus 20 % electricity instead of the current 30 %. According to Gunnelius, implementing a reuse to return loop in the future could even increase efficiency while more lowering temperature.
He continues,” Power companies may also be interested in incorporating excess heat into the return loop.”
Through the use of 100 % clean energy, which is then recycled by being fed into the district heating network, the project now lowers emissions for the local power company.
According to Gunnelius, emissions savings have been estimated at around 30, 000 tonnes per year, despite the fact that they are “kind of a moving target” if today’s emissions per kWh are assumed to be at least 50 % of what could be installed on the site, with an average load of about 70 %.
Although district heating networks also have a long way to go before they can meet their sustainability goals, Finland’s electricity grid is in “quite great shape,” with 97 % carbon-free production in June. But, these can and are getting closer with initiatives like Verne Global’s.
essential components
We’ve reached the point where the essential components of an offering that enables heat recovery from a datacentre have been identified, whether from an application or systems service perspective, according to Drew Turner, head of sector integration at Danfoss.
However, he claims that because water is more or less a great energy transport mechanism, it can be much simpler to realize for an idea with an hydronic, or water-based, cooling system.
According to Turner,” Everything is moving in the direction of included energy system designs, and generally more hydronics or more water.”
The difficulties with using it can frequently be related to proximity, including how to handle the need to cross property lines and numerous customers, ranging from datacenter customers to reuse customers. The great news, according to Turner, is that you can deal with some of those issues with the system design you use.
By giving the datacentre a portion of the solution that fits with their business model, and therefore the heat reuse customer the same solution, he explains, “if the cooling system is hydronic-based, you can address the complications of getting that to another customer.” ” Because datacentres do n’t want to work in the heating industry.”
Power Usage Effectiveness ( PUE) and free cooling, as well as removing obstacles to the construction of new datacentres, are typically of interest to datacenters. Therefore, any heat-reuse service that assists the datacentre operator in achieving those objectives without penalizing them for raising the heat to a level that the following customer can use can be very appealing.
According to Turner,” The solution can be fairly straightforward and beautiful because you’re essentially putting a heat exchanger between the datacenter and the heat reuse customer, and then placing the onus of bringing the temperature up to usable on the customer.”
On its own datacenter and headquarters, Danfoss first completed related “lighthouse” projects. Since then, he has created “multiple systems” for various organizations, all of which are still in the process of being finished, according to him.
According to a lack of infrastructure, the main datacenter hubs of London and Frankfurt appear to be more about. The Nordics are primarily appealing due to the demand side prevalence of existing district energy infrastructure and the need for heating. ” They just so happen to be attractive for datacenter locations due to the average low ambient temperature, which, incidentally, is irrelevant if they are using 100 % of the heat.”
Size matters in the business case, so a heat-reuse system must be created specifically for the situation. Turner tells Computer Weekly that if you’re adding heat reuse to an existing facility, you now have a cooling system to tie in with it, so it can be “arguably better” put into practice. Therefore, it’s not that difficult.
Jakob Jul Jensen, the head of datacenters at the Danish company Danfoss, even mentions implementations in the Netherlands and throughout Finland, including one at a significant Google datacentre. But, one out of every ten datacenters in Denmark has been able to reuse heat, though “probably never at the amount and scale we should have.”
A lack of common funding, on the other hand, in terms of grants to operators, may not be as much of a barrier, even though legislation can help speed up development. He notes that most hydrocarboners are certainly interested in getting access to public-sector support.
Jensen asserts that if they are going to do it, they will pay for it themselves and do not believe that people funding is required. However, some people might lack the drive to incorporate the complexity into their current business model.
Develop cooling, take service levels into account.
Newer technologies with better cooling efficiency may replace tube or coil heat exchangers, and more intelligent datacenter optimization using artificial intelligence ( AI ) and machine learning can be beneficial. If datacenters were to roll back on, say, five nines of availability and latencies for all customers who do n’t actually need them, savings could also be made.
Network storage, network, and storage do n’t always need to be liquid cooled, according to Jensen. Not all servers or CPUs are at a level where that is required. ” You might sell less, but you’ll benefit humanity more.”
Additionally, colocations with fewer than 10 racks commonly experience greater load fluctuations, which results in less repetitive heat production. Yet, they might gain some government assistance, and some Danfoss is aware of are looking into partnerships with “off-takers” like greenhouses instead of district utilities, according to Turner.
Scale is required to invest in the interconnection and supply complication if district energy is used.
long-term accountability
Moreover, the few workers or consultants who are tasked with optimizing energy systems usually have short-term thinking, which suggests the need for mandatory change as well as the possibility of hiring a particular person to drive heat reuse strategies. They also have long-standing accountability for the datacentre’s entire lifecycle.
This would cover the datacentre’s economic lifecycle cost, which would take into account both carbon emissions and embodied carbon. According to Turner, like a holistic perspective is now simply not present from the beginning.
Additionally, Kim Fausing, the chief executive of Danfoss, claims that the potential for using surplus heat in the UK’s 456 datacentres has been disregarded and is actually “extraordinary.”  ,
He claims that” the cost and emissions savings would be very important if these were used to support heating across the nation.” There are 652 eligible excess heat sources in London only, including data centers, underground stations, supermarkets, wastewater treatment plants, and facilities for producing food.Excess heat can add up to 9.5 TWh annually.
According to Fausing, that is about enough to heat 790,000 homes, making it the world’s largest untapped energy source with solutions. To hasten for initiatives across sectors that benefit consumers, businesses, and the environment, policy measures are immediately required. What are we waiting for, he inquires.
