Link to the news article in Finnish.

The European energy sector is in the midst of a historic transition, moving inevitably away from fossil fuels toward carbon-free and electrified solutions. Simultaneously, the explosion of data volumes and computing power (fueled by the rise of AI) is generating massive amounts of thermal energy. These two global megatrends intersect at an opportunity that has, until now, been largely overlooked: the recovery of waste heat from data centers.

This is the greatest untapped energy treasure, which has historically been vented into thin air. Nohewa has made it its mission to change this dynamic by seamlessly integrating data centers into urban district heating networks. In doing so, the heat generated as a byproduct of computing is transformed from a problem into a valuable, cost-effective resource that can replace traditional combustion boilers on a large scale, both in the Nordic countries and internationally.

Case Hamina 80% of City Heating from Google Servers Google’s Hamina data center is a world-class example of the circular economy in action. This Nohewa project captures the heat generated by Google servers and pumps it into the Hamina Energia district heating network. The results are staggering: heat from the data center is sufficient to cover approximately 80 % of the entire city of Hamina’s district heating needs. While this captures only a fraction of the data center's total waste heat, it demonstrates the massive potential involved. If this model were scaled to all new and existing data centers, the transition to electrified heating would take a giant leap forward.

The Data Center as Part of a Modern Energy System

A traditional electric boiler converts electricity into heat at a 1:1 ratio, providing no additional value. A data center enables a highly efficient double benefit: the computing power required by society acts as a massive pre-heater for district heating. Nohewa’s technology converts this waste heat into a high-efficiency energy source, cutting the power demand for district heating to a fraction of what traditional systems consume.

In heat pump technology, efficiency is measured by the COP (Coefficient of Performance),which indicates how many units of heat are obtained for every one unit of electricity used. Data centers provide an exceptionally warm and stable source of waste heat, raising efficiency to a completely new level compared to traditional sources.

In a typical facility, one megawatt-hour of electricity can produce approximately four megawatt-hours of heat. However, as technology moves toward Direct Liquid Cooling (DLC), the potential rises to over sevenfold. This means that with one megawatt-hour of electricity, we can produce over seven megawatt-hours of heat.

Heatzilla® – A Modular Answer to an Urgent Need

Investment decisions in the energy sector have traditionally been slow and expensive. Nohewa has broken this barrier with the Heatzilla® concept. This is a modular, "plug-and-play" heat pump plant that can be delivered and commissioned in a fraction of the time required for traditional solutions.

Heatzilla is built to grow. Its modularity allows for flexible capacity expansion as the data center's IT load increases or the energy company's district heating network expands. This minimizes risks for both parties and ensures a rapid return on investment. Our customers have reported measuring payback periods in months rather than years.

The Future is Now – Regulation is Forcing Action

Regulatory pressure in Europe is mounting, and waste heat recovery is becoming a legal requirement for data center operations in many countries. France's recent PPE3 strategy (2025–2035) and the DDADUE law confirmed in early 2025 change the rules of the game: data centers are no longer seen as passive consumers, but as “reverse power plants” that must give a portion of their energy back to society.

In France, large projects will soon be required to present a concrete waste heat strategy as a condition for grid connection, with a target to utilize up to 60% of waste heat by 2030. In Germany, similar developments are seen in the Energy Efficiency Act (EnEfG), which mandates that new operators actively utilize their waste heat.

In Finland, the situation is currently in flux. The transition of data centers to the general electricity tax class in July 2026 makes waste heat recovery even more critical. Heat recovery is becoming an essential means for data centers to compensate for rising energy costs.

We ensure that digital infrastructure turns into a sustainable benefit for all parties. Nohewa is Europe’s leading expert in data center waste heat recovery, understanding the logic of both bits and district heating. Our vision is clear: No Heat Wasted. The data center is no longer an energy hog, but a resource-wise partner, heating its neighbors bit by bit.