Data centers support the modern technologies we rely on, but they also produce enormous amounts of waste heat.
Because servers and computing equipment are sensitive to temperature, operators spend significant effort and expense removing that heat — sometimes even locating facilities in cooler climates to reduce cooling costs. But what if that waste heat didn’t have to be discarded and could instead be recovered and reused?
In collaboration with HIVE Digital, this article explains how data centers are progressing toward recovering and repurposing their waste heat, turning a liability into a resource.
How Much Heat Does a Data Center Produce?
To put the scale in perspective, imagine a mid-sized cryptocurrency operation using 1,000 units of one of the most energy-efficient mining machines available today, the Antminer S21 Hydro. Each unit draws about 5,360 watts and consumes roughly 47 MWh per year.
Multiply that by 1,000 machines and the total waste heat exceeds 160 billion BTU — an amount of energy sufficient to heat over 4,600 average American homes for a year. To illustrate the scale in a different way, that quantity of heat could, in theory, pop about 463,803 metric tons of popcorn during Oscar season (with somewhat less melted butter required).
How Does Waste Heat Recovery Work?
Waste heat recovery typically captures thermal energy from servers and cooling systems using heat exchangers, then redirects it into district heating networks or local heating systems. Cooler air or fluid returns to the data center and the cycle repeats, creating a closed-loop approach to temperature management and energy reuse.
Liquid cooling is the most efficient method for capturing and transferring waste heat because water can carry roughly four times as much heat as air per unit volume. By circulating a liquid coolant through racks and heat exchangers, data centers can transfer a concentrated thermal stream to nearby facilities that need heat, such as residential buildings, industrial processes, pools, or greenhouses.
Across the world, data centers are already supplying waste heat to diverse end uses: trout farms in Norway, research facilities in the United States, and swimming pools in France are examples where recovered heat is put to practical use.
A Greener Future for Data Centers
Until recently, waste heat recovery has been largely voluntary and driven by operators who want to reduce their environmental footprint. Regulatory changes, however, are shifting this dynamic toward broader adoption.
In the Netherlands, Amsterdam and Haarlemmermeer are mandating that all new data centers reuse their waste heat. Norway requires heat recovery for new data centers above 2 MW. Denmark has chosen an incentive-based approach, offering tax breaks and financial support to encourage reuse projects. At the end of 2023, the EU’s Energy Efficiency Directive came into effect, requiring data centers to either reuse their waste heat or demonstrate that recovery would be technically or economically unfeasible.
These policy shifts are accelerating the integration of heat recovery into data center design and operation, especially across Europe. As regulators tighten standards, operators will increasingly pair efficient computing with systems that redirect heat to local communities and industries.
HIVE Digital Provides Sustainable Heat
HIVE Digital is already reclaiming waste heat from data center operations in Canada and Sweden. Their 30 MW facility in Lachute, Québec, supplies heat to a 200,000-square-foot industrial site, while the 32 MW site in Boden, Sweden — located just south of the Arctic Circle — heats a 90,000-square-foot greenhouse, contributing to local, sustainably grown produce.
Data centers will continue to grow as a fundamental part of the digital economy, but that growth need not come at the expense of efficiency or environmental responsibility. Recovering waste heat turns an unavoidable byproduct of high-performance computing into a valuable resource — reducing emissions, lowering energy costs, and supplying useful heat to buildings, industry, and agriculture.
As technologies like liquid cooling mature and policy frameworks evolve, waste heat recovery is becoming both a practical and an economic option for data center operators. The result is a path toward more sustainable computing infrastructure that benefits operators, communities, and the broader energy system.