At first glance, Bathhouse spa in Brooklyn appears similar to other high-end spas. However, what distinguishes it is hidden from view: a storage room filled with cryptocurrency-mining computers that generate both bitcoins and the heat used to warm the spa’s pools, marble hammams, and showers.
When cofounder Jason Goodman opened Bathhouse’s first location in Williamsburg in 2019, he initially used conventional pool heaters. After delving into the world of bitcoin, he discovered an innovative way to integrate cryptocurrency mining into his business model. The process of mining, where specialized computers make trillions of guesses per second to earn bitcoins, consumes significant amounts of electricity, producing substantial heat that is typically wasted.
“I thought, ‘That’s interesting—we need heat,'” Goodman recalls. Typically, mining facilities use fans or water to cool their computers. Bathhouse cleverly utilizes pools of water, a prominent spa feature, to serve this purpose. It takes six miners, each about the size of an Xbox One console, to maintain a hot tub at 104 °F. At Bathhouse’s Williamsburg location, these miners operate quietly within two large tanks in a storage closet, alongside liquor bottles and teas. To keep them cool and quiet, the units are immersed in non-conductive oil, which absorbs the heat and is pumped through tubes beneath the hot tubs and hammams.
The spa also employs mining boilers that cool the computers by circulating cold water, which emerges at 170 °F. A thermal battery stores excess heat for future use. Goodman explains that while his spas aren’t saving energy by using bitcoin miners for heat, they’re not consuming more energy than they would with conventional heating methods either. “I’m just inserting miners into that chain,” he clarifies.
Goodman isn’t alone in recognizing the potential of heating with cryptocurrency. In Finland, Marathon Digital Holdings transformed fleets of bitcoin miners into a district heating system, warming the homes of 80,000 residents. HeatCore, an energy service provider, has used bitcoin mining to heat a commercial office building in China and maintain pool temperatures for fish farming. They are set to begin a pilot project this year to heat seawater for desalination.
However, environmentalists are concerned about the energy-intensive nature of bitcoin mining. As of mid-March, the energy required for a single bitcoin transaction was equivalent to the energy consumed by an average US household over 47.2 days, according to the Bitcoin Energy Consumption Index. Economist Alex de Vries points out that while some cryptocurrencies have moved away from energy-intensive mining, bitcoin users are resistant to change.
One significant barrier to using bitcoin for heating is that the heat can only be transported short distances before it dissipates. De Vries views this as a niche application, stating, “It’s just not competitive, and you can’t make it work at a large scale.” While increasing the use of renewable energy sources will make crypto mining cleaner, it doesn’t necessarily make it sustainable, according to Kaveh Madani of the United Nations University Institute for Water, Environment, and Health. Mining consumes valuable resources that could otherwise meet existing energy needs.
For Goodman, the benefits of relaxing in bitcoin-heated water justify the energy use. It not only soothes the muscles and calms the mind but also challenges current economic structures. The innovative approach combines luxury spa experiences with cutting-edge technology, creating a unique offering in the wellness industry.
