Bitcoin mining is an energy-intensive process that generates a significant amount of heat–the main other output from the process besides Bitcoin.
Many innovative solutions have been developed to try to capture this ‘waste heat’ over the years, such as for farming or residential heating. Still, most people dispose of the heat through either air- or immersion-cooling systems. In this article, we will delve into why this technology is starting to be the choice for many of the listed miners in North America.
Immersion cooling surpasses traditional air- or liquid-cooling methods by offering superior heat dissipation. By submerging mining hardware directly in a non-conductive coolant, heat is rapidly transferred away from the components, resulting in lower operating temperatures. Furthermore, the sealed environment provided by immersion cooling keeps the miner machines clean and significantly reduces maintenance requirements, thereby enhancing performance and extending the lifespan of the mining equipment.
Cooling plays a crucial role in the energy consumption of Bitcoin mining operations. However, immersion cooling allows for precise temperature control, reducing the need for excessive cooling infrastructure. This translates to significant energy savings, improved efficiency, and reduced costs required to maintain optimal operating temperatures.
By eliminating the necessity for large air-cooling systems, mining rigs can be densely packed, optimizing the utilization of physical space. This advantage becomes particularly valuable in locations where space is limited, as it enables increased computational power in a smaller footprint.
Immersion cooling also eliminates the need for fans and ventilation systems, which generate substantial noise. Although fans are still utilized in immersion cooling for cooling the heat exchanger, they are larger and produce significantly less noise. Consequently, the mining environment becomes quieter, reducing noise pollution and improving overall working conditions. This benefit is especially advantageous for mining farms located in residential or noise-sensitive areas.
One should not underestimate the importance of firmware in immersion-cooling technology. Firmware is a critical software component responsible for controlling the temperature of the liquid coolant. By monitoring and adjusting the coolant temperature as needed, firmware ensures optimal cooling performance. It also prevents overheating and addresses other issues associated with immersion cooling. Additionally, firmware can control other aspects of the cooling system, such as fan speed and pump speed, further optimizing performance and reducing energy consumption.
With its superior heat dissipation capabilities, immersion cooling enables better temperature control, reducing the risk of overheating during overclocking. This allows Bitcoin miners to push their equipment to its limits, potentially increasing mining efficiency and profitability.
Whinstone and Helios
Large-scale miner adoption of immersion is newer than most people think. Although available since the early days of ASIC mining, it wasn’t until 2021 that most public companies noted their planned use of immersion, such as Argo Blockchain’s announced Helios site in Dickens County, Texas, with 200 MW of immersion. Riot Platforms followed with a public statement of its intention to also build a 200 MW immersion-cooling facility at its Whinstone site, in Rockdale, Texas.
The two facilities have now been operating their immersion-cooling technology in excess of 12 months, but there have yet to be any notable updates highlighting metrics associated or the benefits described above. In fact, damage incurred to Buildings F and G at Whinstone, which housed the immersion-cooling technology, during the severe winter storms in Texas in late December 2022, effectively put 1.9 EH/s offline. The company anticipates restoring this self-mining hashrate capacity in the second half of 2023.
It is worth noting that the pursuit of immersion has come behind a gloomier performance for these two miners. If you consider the self-mining production of the last 12 months for both these companies, Riot Platforms has averaged 78 Bitcoin per EH/s, with Argo Blockchain achieving 77 Bitcoin per EH/s. When you compare this with the top-performing miner of the last 12 months, Hive Blockchain (HIVE) achieved an average of 114 Bitcoin per EH/s.
(However, it should also be noted that Riot Platforms, and likely Argo Blockchain, participate in energy demand response programs that pay for miners to be offline during peak hours).
Two other immersion builds are of importance: Cleanspark and Marathon Digital.
Cleanspark (CLSK) has installed immersion-cooling systems in its 20 MW Norcross, Georgia, farm, enabling the company to benefit from lower operating costs and greater hashrate capacity, thereby increasing its margin and maximizing financial gains. Details of the build are sparing, but one of the builders is the founder of TMGcore.
Marathon Digital recently announced that it had formed a joint venture within the Abu Dhabi Global Markets (ADGM) with the firm ZeroTwo in order to develop and run two new sites, the larger 200 MW facility in Masdar City, with a further 50 MW facility to be located in the port zone of Mina Zayed, to be utilized for digital asset mining. With the weather in Abu Dhabi not conducive to air-cooled facilities, both sites will be utilizing immersion-cooling technology.
The company had previously placed an order for 78,000 S19 XPs in December 2021 and was extremely bullish on the use of this technology, having carried out its own studies. Marathon Digital is going to be using a second-generation solution in the UAE and will then begin to deploy throughout its other locations. It will be interesting to see how the results compare to the likes of Argo Blockchain and Riot Platforms once fully up and running.
It should be acknowledged at the outset that this technology requires a significant amount of upfront investment. The specialized cooling tanks, coolants, and associated infrastructure will be more expensive than traditional cooling methods. However, it is essential to consider the long-term benefits and potential energy savings when evaluating the return on investment.
Immersion-cooling technology, while efficient, demands careful maintenance and monitoring of the coolant for contaminants–and timely replacement is necessary. The cleaning and maintenance processes can be time-consuming and require expertise, adding to the overall operational complexity.
Although mining hardware components in a liquid environment decrease the risk of corrosion, they can increase the swell in plastic and rubber components in the mining machine, and if the rubber swells too much, the capacitors will fail.
While modern immersion-cooling solutions use non-conductive coolants, there is still a potential risk of coolant leakage or seepage, which could damage the components. Regular inspections and preventive measures are necessary to mitigate this risk.
Scaling up an immersion-cooling-based mining operation can present logistical challenges, especially as the number of mining rigs increases and managing coolant circulation, heat dissipation, and maintenance becomes more complex.
As we have seen the speed of innovation in recent years with the efficiency of mining machines, it can be reasonably expected that adopters using first-generation immersion cooling will be quickly replaced by later-generation innovation and enhancements to the technology.
Immersion-cooling technology offers several advantages for Bitcoin mining, including enhanced heat dissipation, improved energy efficiency, higher mining density, noise reduction, and the potential for overclocking. However, it is important to consider the disadvantages associated with this technology, such as initial setup costs, complex maintenance requirements, the potential for component corrosion, limited compatibility, and scalability challenges.
When considering whether to implement immersion cooling in a Bitcoin mining operation, miners should evaluate their specific requirements, budget constraints, and available resources. Immersion cooling can be a highly efficient and effective solution for cooling mining equipment, particularly in situations where heat dissipation and energy efficiency are critical factors.
However, careful planning, proper maintenance, and regular monitoring are essential to ensure the long-term success and profitability of immersion-cooling technology in Bitcoin mining operations.
Fun Fact: Mercedes AMG is probably the first mass-produced vehicle that used immersion-cooling technology to keep the high-performance battery cooled. The electrolyte fluid Mercedes used in the process is the same fluid that Argo Blockchain is currently using at the Helios facility.