There’s no denying that bitcoin mining uses a lot of energy. According to one estimate, it takes as much energy to mine a single bitcoin block as it does to power 28 U.S. homes for an entire day. To strengthen its long-term position, bitcoin advocates must refute critics’ claims that bitcoin mining is too energy-intensive. And some miners are doing just that. In the fourth quarter of 2021, bitcoin achieved a major inflection point, with renewables powering over 50% of mining farms. This pivot toward sustainable sources like solar, gas flares, wind, and hydroelectric power could very well define the future success of the cryptocurrency movement. Still, there’s one additional key area where sustainability will come into play: cooling. Let’s take a look at the state of the bitcoin ecosystem today and how more efficient cooling will drive sustainability initiatives.
The State of Bitcoin Mining Today
Industrial miners have thousands of computers whirring away in a myriad of locations ranging from containers in the desert to warehouses that resemble data centers. Their calculations are used to verify transactions within the bitcoin network, and their completion unlocks new bitcoin. As the number of miners in the network increases, the calculations become more complicated. By early 2022, the amount of computing power required had surpassed all previous records, forcing miners to invest in even more powerful equipment and bigger server farms to maintain a competitive edge. Investment in more energy-efficient equipment has miners investigating new cooling methods to reduce energy consumption while remaining competitive.
Air Cooling Hits Its Limit in Bitcoin Mining
Let’s start with the status quo in cooling mining farms: air cooling. Air coolers work by circulating air around the miner to dissipate heat. This method is simple, effective, and relatively inexpensive. However, it has its limits. And as competition intensifies, miners must find an increasingly elusive edge to remain profitable, which often comes in lower electricity bills.
This has led miners to move their rigs to locations with cooler climates and lower temperatures, such as Iceland, Sweden, and Canada. However, these areas are quickly becoming saturated with mining operations, driving up land and energy costs. In response, some miners are turning to more efficient cooling methods, such as liquid cooling.
Liquid Cooling: The Sustainable Option for Bitcoin Miners
Liquid cooling is increasingly seen as the way of the future for bitcoin mining. The benefits of liquid cooling are clear: it helps extend device lifetime, improves performance, and offers a much higher energy-efficiency to power ratio than air cooling. Moreover, it can allow miners to pack more rigs into a smaller space, which is crucial as mining farms grow.
Today’s most prevalent liquid cooling solution in the mining community is immersion cooling. This method works by submerging the entire mining rig in dielectric oil. The oil dissipates heat away from the sensitive components, and the rig is cooled without any external fans. Immersion cooling has its drawbacks; it’s more expensive than most other efficient cooling alternatives, can be challenging to deploy at scale, and when miners inevitably require maintenance, it takes time to clean off the oil.
Another form of liquid cooling that has gained traction in the bitcoin mining community is water cooling. Water cooling enables miners to adopt liquid cooling in an air-cooled form factor, creating high-density deployments and scaling better than immersion cooling.
What is Water Cooling, and How Does it Help with Sustainability?
Water cooling offers several advantages over immersion cooling, which is making it the preferred choice for many miners. Compared to immersion, water cooling with microconvective technology enables enhanced overclocking, halves energy expenses for cooling, and practically eliminates fluid costs. Unlike typical heat sinks or cold plates that pass fluid over a surface, water cooling with microconvective cooling™ uses arrays of fluid jets to cool the ASICs right where the heat is generated, resulting in unprecedented performance and unmatched temperature uniformity. By using water to cool the ASICs, miners can run at a higher hash rate for a longer period of time without overloading the system and shutting down. Additionally, water cooling with microconvective technology is low maintenance, making it a more cost-effective option in the long run.
Let’s evaluate how water cooling with microconvective technology enables miners to have more efficient mining farms that can reuse heat and almost eliminate water consumption while using environmentally safe fluids.
PUE and Its Importance in Energy Efficiency: What Miners Need to Know
What is Power Usage Effectiveness, and why is it important for bitcoin mining? Power Usage Effectiveness (PUE) is a metric used to measure the efficiency of data center operations or, in mining, how efficiently a mining farm operates. It is calculated by dividing the total amount of power consumed by the mining farm by the power consumed by the miner rigs. A PUE of 1.0 means that the rigs use all the power consumed by the mining farm, and a PUE of 2.0 means that the mining farm is using twice as much power as the rigs (e.g. for lighting, overhead, and cooling). Thus, a lower PUE means that less energy is wasted, which is good for the environment and improves sustainability.
Water-cooled bitcoin mining rigs that use microconvective cooling™ have a PUE of 1.03. This means that for every 100 watts of power consumed by the mining rig, only 3 watts are lost to heat. Compare this to air-cooled rigs, which have a PUE of 1.3 or higher, and it’s easy to see why water cooling is the more sustainable option.
Closed-Loop Recycled Water Cooling is the Greener Cooling Alternative
Another advantage of water cooling is that it enables miners to recycle the water used to cool the rigs. From Florida consuming water faster than it can be replaced to California facing extreme drought conditions, the U.S. rapidly recognizes that even though water is a renewable resource, it’s not unlimited. The mining industry, which is expected to use 150 terawatt-hours of electricity this year, has a responsibility to adopt sustainable practices that won’t deplete local water resources.
How can miners use water sustainably? Mining farms that use water cooling with microconvective technology are outfitted with a closed-loop, recirculating water system. This means that the same water is used over and over again, significantly reducing the amount of water needed to operate the mining farm. Closed-loop systems only use a few gallons of water throughout the system’s lifetime. In contrast to closed-looped systems, some of the most well-known water-cooled mining rigs rely on facility connections that can use 10,000 gallons of water per day, depleting local lakes and water sources.
As water shortages pop up all over the United States, miners have less access to water for cooling their rigs. Recycled water is a great way to reduce the demand for fresh water and improve sustainability.
Eliminate Oil from Your Mining Farms
Another advantage of water cooling is that it eliminates the need for oil-based coolants. Pumping oil consumes more energy than water due to its high viscosity. When you use less energy, you save money on your electric bill. This is one of the biggest advantages of water cooling.
In addition to being less energy-efficient, oil-based coolants are also more expensive and have a larger environmental impact. They’re made from petroleum, a non-renewable resource, and when they leak, they can contaminate soil and water. Water-based coolants, on the other hand, are non-toxic and biodegradable. As such, water cooling is a more sustainable option for miners looking to improve their efficiency.
The Future of Bitcoin Mining is Green
As the bitcoin mining industry matures, we will see a continued focus on efficiency and sustainability. Switching to renewable energy and committing to reducing carbon footprints will put miners in a better position to win over communities, partners, and investors. Water cooling is one of the most efficient and environmentally friendly ways to keep mining rigs cool, and it’ll only become more popular as miners search for methods to become greener.