1. Exploring solutions to the surprising energy consumption of Bitcoin mining
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  • Exploring solutions to the surprising energy consumption of Bitcoin mining

    By Kelly Hall, 3M Storyteller and Eliot Popko, 3M Videographer

    Still image from video about energy use for Bitcoin mining
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    • Bitcoin mining – it is a trending topic – but also one that is a bit abstract and complex to understand.

      In short, it is a process for acquiring bitcoin, a cryptocurrency that’s part of a global payment system. Bitcoin miners use special software to solve mathematical algorithms. In return, they are issued bitcoins.

    • Closeup image inside a data center

      You may be surprised to know that there is a significant amount of energy required to support these algorithms that facilitate the Bitcoin mining process.

      “The energy required to enable bitcoin and the blockchain type of applications that make bitcoin work is energy intensive,” says Laura Nereng, sustainability leader for the Electronics and Energy Business Group at 3M.

      Just how much energy are we talking about? Some studies say that the energy consumption of the entire Bitcoin network has grown at a rate of 25 percent in one single month.

      “The crazy thing to think about with respect to Bitcoin mining is that, depending on which estimates you look at, Bitcoin mining could require as much energy in 2020 as we used in the whole world for everything in 2017,” says Laura. “If that is the case, this would be a lot of extra energy being used.”

      Other studies show that the electricity used in a single Bitcoin transaction could power a house for a month.

      Laura says this energy use will only continue to increase as Bitcoin technologies continue to evolve. “Blockchain, the technology that enables Bitcoin mining, will continue to get implemented in different industrial and commercial segments for the benefits it will bring,” she says. “Energy will be needed for data processing.”

    • “Innovation will have to take place.” – Laura Nereng, 3M scientist

      Finding cooler solutions

      Scientists are working with the data center industry to prioritize lowering the amount of energy needed.

      One solution involves utilizing immersion cooling fluids to cool data centers.

      “The cooling technology is particularly important to Bitcoin mining, because of how much energy that is required to carry out Bitcoin mining computationally,” says Laura. “Because this process will use a significant amount of energy, there is a growing demand for cooling technologies. To be able to do that efficiently, innovation will have to take place.”

      One unique cooling approach is what 3M scientists have coined “open-bath immersion cooling” or “passive two-phase immersion cooling,” says Phil Tuma, an applications development specialist who works with heat transfer fluids at 3M. Here is how it works: “This cooling process happens in vessels that are maintained at atmospheric pressure using control systems,” explains Phil. “Because the systems are maintained at atmospheric pressure, they are able to be opened at any time for servicing, allowing you to remove one server while other servers remain operational and able to continue boiling.”

      Although this approach had not been practiced for applications like Bitcoin mining before, it caught the attention of Allied Control, a leading immersion cooling pioneer for high-density applications. This was the beginning of the bitcoin industry’s venture into immersion cooling.

    • Closeup image looking down into an immersion cooling tank

      A case study: cooling bitcoin

      “Two young entrepreneurs from Allied Control approached us,” says Phil. “They saw some videos on two-phase immersion cooling and were intrigued by the possibilities of using it in Bitcoin mining.”

      “Back in 2012, we set up our company in Hong Kong purely for the purpose of Bitcoin mining,” says Kar-Wing Lau, CEO at Allied Control. “At the beginning, we were still considering using air conditioning for cooling our bitcoin mine in the sub-tropical climate.”

      As they looked to build their first large Bitcoin mining deployment, Allied Control was faced with barriers. “It is quite hot and humid in Hong Kong. It would be very difficult to run air-conditioning very efficiently,” says Kar-Wing.

      Phil adds, “It was inconceivable for them to build a traditional data center in that space.”

      “We were also considering different kinds of cooling methodologies – such as water cooling, oil-immersion cooling and also two-phase immersion cooling,” says Kar-Wing. “When we took a deeper look into 3M™ Novec™ Engineered Fluids using two-phase immersion cooling, we were quite fascinated by the possibilities.”

      While they knew that no one had ever implemented two-phase immersion cooling on a large scale for data-center cooling at the time, Allied Control was willing to take the plunge. Kar-Wing explains that by utilizing two-phase immersion cooling, the company was able to set up the world’s largest immersion cooling data center at the time in only six months, including time for research and development. The center had an IT critical load of 70 kilowatts. Shortly thereafter, Allied Control set up their next immersion cooling data center with an IT critical load of 500 kilowatts and room to grow.

      The benefit was multi-fold.

      “Utilizing the passive two-phase immersion cooling approach allowed Allied Control to deploy in a conventional office space, decreasing the cost of the facility,” explains Phil. “It also allowed them to operate much more efficiently, so that the amount of power required was much lower, and therefore less expensive.”

      A few years later, Allied Control was presented with yet another challenge, as they were acquired by the BitFury Group, a leading blockchain technology provider, to facilitate a new data center.

      “For BitFury, we set up yet again the world’s largest immersion cooling data center in the Eastern European country of Georgia,” says Kar-Wing.

      Kar-Wing explains that while some bitcoin miners have explored putting their services into data centers, many have been hesitant, since this can be a costly process. The BitFury Group thought differently. They were considering not only the initial costs to set up their data center, but also the operating cost for the 40-megawatt facility. “It was very attractive to save as much as possible on cooling electricity,” says Kar-Wing.

      Passive two-phase immersion cooling helped meet this need. “With passive two-phase immersion cooling, we are able to increase the density of our systems quite a lot. If we were to set up the data center in Georgia with traditional air cooling, it would have required multiple times the floor space,” says Kar-Wing. “With a much smaller data center, we are also able to save a lot on construction costs. These were very compelling reasons for the BitFury Group to take a look at immersion cooling.”

    • A collaborative approach

      It is no question that creating solutions to cooling data centers requires innovative ideas. Kar-Wing hopes that liquid immersion cooling is among those considered as data centers scale into the future.

      “We certainly hope that the industry is seeing liquid cooling – specifically passive two-phase immersion cooling – as an interesting way to go forward to deal with the very high electrical densities of servers today and into the future,” he says.

      The desire to find solutions is an industry-wide collaboration.

      “The innovative cooling fluids cannot work alone,” says Laura. “While 3M may provide a new means of cooling, it will also require electronics manufacturers to pack the electronics in data centers tighter.”

    Learn more

    3M scientists and engineers are working with some of the largest cloud providers and social networks to develop solutions to help make data centers more efficient. 3M’s new documentary, ‘Data Driven,’ explores the importance of the data center industry and the challenges it faces as it scales into the future.