Gary Testa opened his session at Mining Disrupt Miami 2024 with a problem many operators in the room recognized: miners sitting on the sidelines. Power costs had risen, margins were gone, and they held devices and infrastructure they could neither sell nor run at a profit. Testa, President and CEO of Engineered Fluids, offered what he called a secondary business plan: keep the miners, the immersion tanks and the know-how, and find someone who will pay for the heat.
The session was recorded at Mining Disrupt Miami 2024, held June 24–26, 2024. Bitcoin traded at $61,272 then; it is $81,433 now. The next Mining Disrupt runs March 22 to 24, 2027 in Irving, Texas.
Miners on the sidelines
Testa's starting point was the operator who cannot move. Not everyone can pick up and relocate to a place with cheap hydropower, he said, and plenty of miners hold something like a thousand devices with nowhere profitable to plug them in. He put numbers on it: with miners overclocked to 120 percent and power at 10 cents, the mine in his example lost two dollars every hour.
I want to talk to you about a secondary business plan.
Gary Testa · 1:14
His argument rests on a simple property of mining hardware. Miners are very efficient at turning electricity into heat, and an immersion system captures nearly all of it in the fluid. Most sites dry-cool that fluid and throw the energy away. Testa's plan is to sell it instead, to a buyer who will cover the electricity that runs the mine.
Why 60 degrees Celsius matters
The match he chose was beer. Pasteurization happens at about 60 degrees Celsius, and a typical mining immersion tank runs at about the same temperature. A brewery Engineered Fluids works with produces about 30,000 barrels a year and needs, on average, about 1,000 liters of water held at 60 degrees Celsius to pasteurize two barrels. It heated that water with giant electric water heaters or gas, and Testa called pasteurization one of its biggest single operating costs after brewing and water.
Pasteurization of beer happens to occur at the magic 60 degrees Celsius number.
Gary Testa · 4:35
To turn a mine into a heat source, Testa said, three things are needed: a water pump, a liquid-to-liquid heat exchanger, and a buyer who will use the heat. Ten S19J Pros running in immersion heat enough water to pasteurize two barrels. The brewery was going to pay for that energy anyway: he put its draw at 46.25 kilowatt hours against the 46.3 the miners need, and the miners give off the same heat while they hash.
The brewery deal
Scaled up, the numbers in his example were 16 barrels an hour on 80 miners, saving the brewery $40,000 over that run. Testa conceded these are not big numbers, but said they beat sitting on the sidelines with idle equipment.
if I do 16 barrels an hour using 80 miners, we can save that brewery 40,000 dollars in that run.
Gary Testa · 8:24
Engineered Fluids brokered the deal for a miner who had come to it with an existing immersion system and unprofitable machines. The brewery and the miner split the profits 40-60, with the miner taking the larger share because it kept operating the hardware. The miner also gained access to the brewery's other sites.
not to mention the free beer.
Gary Testa · 13:27
The integration itself was small. The team added two pipes to the existing mining system, and because the brewery already ran 480-volt three-phase power, the miners could use a 480-volt immersion power supply; Engineered Fluids sells 7,000-watt units for overclocking. Testa said 480-volt power saves on wiring, since the copper is smaller and the switchboards and breakers are standard US parts. Once the first system was in, the brewery looked for more places to use the heat, and its owners, who run 30 breweries across the United States, asked for systems at all of them.
A better pitch for the zoning board
Testa tied the model to a problem he said many operators now face: getting a mine approved. He described the antipathy toward mining in plain terms: claims that it is a waste, that it burns useless electricity, that it has no socially redemptive features. Its benefits, he said, are not obvious to the average person on a zoning board, and noise and health and safety are real issues.
A heat-reuse proposal changes that conversation. Testa said he can walk into any local zoning committee and explain that a mine will save a local brewery money, and that is a case people understand. The brewery was already buying the power. The project simply swapped its water heaters, which do one job, for immersion miners that do two.
Heat is fungible
The brewery was one example. Testa's broader point was that heat is fungible and can be sold. Hospitals use a lot of heat, he said, and Engineered Fluids counts 80 separate applications. One fish farm is heated entirely with mining; tilapia, he noted, grow better in water at about 80 degrees Fahrenheit.
He gave operators three things to look for. First, the highest exit temperature they can get from the tank, which depends on the device makers. Second, continual processes: the brewery brews only five days a week, so its miners ran only five days a week. Third, the coolant. If it is not food grade and not self-extinguishing, he warned, the insurance company may refuse it at the site. He also said mineral-oil-based products are causing allergic reactions, and that Engineered Fluids has replaced several competitors' fluids for that reason.
Build me a miner that I can use to produce 80 to 90 degree fluid, and I can rule the world.
Gary Testa · 15:59
That request was aimed at the hardware makers. Many industrial processes need heat in that range, Testa said, and a hotter tank would open them to miners. Until then, his case for operators with idle machines was practical: find a business that already pays for heat, install the system next to it, and keep mining.