Using Waste Heat from Data Centres: Turning Digital Heat into Community Warmth __

Imagine this: Every time you watch a series, train an AI model, or back up your company's data, a data centre somewhere is hard at work – and all the electricity powering those servers ends up as heat. 

Instead of wasting that warmth, what if we captured it and used it to heat neighborhoods, greenhouses, or even Olympic pools?

That’s not just a vision for the future - it’s happening now.

Why data centre heat matters more than ever

Today’s data centres are the engines of our digital world – but they’re also approaching a new kind of energy milestone. The latest International Energy Agency (IEA) analysis projects global data centre electricity use could reach about 945 terawatt-hours by 2030, nearly double the demand seen just a few years ago. That means a massive, ever-growing supply of usable waste heat – if we know how to tap into it.

Why does so much heat generate?

• IT load equals heat: CPU and GPU processors emit up to 95% of their electrical power as heat.
• Cooling is the second biggest energy guzzler: Conventional air cooling consumes up to 40% of a data centre's electricity – energy that also ends up as waste heat.

So far, this potential remains untapped, but regulations are catching up. Most of this heat still ends up in the atmosphere. The revised EU Energy Efficiency Directive (EU/2023/1791) requires operators to report detailed performance data from September 2024 and promotes the integration of waste heat from data centres into heating and cooling networks – a clear investment trigger for operators and municipalities.

The role of high-performance pipe systems

To ensure that heat flows with minimal loss, pipes must be pressure- and temperature-resistant, corrosion-free, and quick and easy to install. 

The hotter the heat captured, the more efficiently it can be piped directly into neighbourhood or city heating networks – sometimes with only a modest temperature boost from a heat pump.

Data Centre Cooling System Temperature Ranges and Heat Network Integration Potential

From the data centre to practical use

Waste heat from data centres is available around the clock and is clean, but in most cases it is simply “given away.” If it were specifically extracted, it could provide a reliable, low‑carbon heat source for municipal utilities, neighbourhood developers, and industry. Three questions are crucial: Where does the heat go? What is its temperature level? How close is the consumer?

No longer a by-product: waste heat becomes a resource

Forward-thinking data centres are shifting their role from power-users to community partners. Instead of letting waste heat literally go up in smoke, modern designs transform it into a valuable, low‑carbon heating resource for cities.

From rack to district: how the heat gets out

• Neighbourhoods: Server cooling loops often deliver water at 35–50 °C. A large heat pump raises it for local networks (<80 °C) that supply homes, apartments, and mixed‑use blocks.
• Municipal/legacy networks: Heat can also be raised to >90 °C for direct input into large city grids and older “steam era” district heating systems.

The main message: Data centres are no longer energy “islands” – with the right plumbing and planning, they are becoming anchors in the low‑carbon grid.

Success stories from around the world

• Finland: In Espoo, Kauniainen, and Kirkkonummi, Microsoft and energy utility Fortum are partnering to supply around 40% of district heating demand – serving 250,000 people – using waste heat from new data centres. This is being called one of the world’s largest data centre heat recovery projects, and is scheduled to go live by 2026.^[3][4]
• France: At the Equinix PA10 data centre in Saint-Denis, Paris, server heat is captured and upgraded with heat pumps to supply about 10,000 MWh per year – enough to heat roughly 1,000 homes or maintain the Olympic Aquatics Centre’s pools at a comfortable 27–28 °C all year.
• Denmark: Meta’s (Facebook’s) vast Odense data campus recovers its waste heat to serve up to 11,000 households through Odense’s district heating network – a stable, 24/7 renewable resource for the city.^[8]

Canada: Emerging leader in data centre heat reuse

Canada is getting in on the action too – especially as federal and provincial clean energy policies accelerate district energy development.

• Hamilton, Ontario: The Hamilton Steelport redevelopment and Hamilton Community Energy are collaborating on industrial-scale district energy systems, including feasibility studies to harness waste heat from both steelmaking and future data centres.^{[9][10][11][12]}
• Quebec and Eastern Canada: In Quebec, pioneering firms like QScale are leading the charge on data centre heat reuse. QScale’s flagship Lévis campus is designed to supply surplus heat to neighbouring greenhouses and developing local energy networks. Other large-scale digital and industrial projects across Eastern Canada (and Quebec more broadly) are embracing similar models, marking a regional shift towards sustainable heat recycling.

Why operators and municipalities benefit 

Recycling server heat significantly reduces a site's PUE and replaces energy-intensive cooling towers or fans, lowering both electricity consumption and OPEX. At the same time, heat purchase agreements are created, turning a pure cost into a reliable cash flow. BCG analyses show that if a data centre supplies its waste heat directly to neighbouring buildings, the investment costs are usually recouped after around three years. If the heat is fed via a small local heating network to consumers within a radius of up to two kilometres, the payback period is typically less than five years.

Another lever is decarbonization : every megawatt-hour of recovered server heat replaces fossil fuel energy and improves the ESG balance sheet. This factor is becoming increasingly significant financially in light of EU Taxonomy, CSRD reporting requirements, and rising CO₂ prices.

Waste heat as a business model 

If heat utilisation is considered during the design phase, short supply routes and contractually secured purchase points can be established. Operators sell their heat via long-term HPAs, municipalities benefit from predictable CO₂ savings, and investors value the location more highly due to additional cash flows and regulatory advantages. In short, bringing server heat within reach of a consumer transforms a cost centre into a scalable revenue stream while advancing the heat transition.

Technical requirements for successful waste heat utilisation in data centres

Waste heat from the server room only becomes a viable business model when key factors – hydraulic separation, temperature increase, and low-loss transport – are carefully integrated. Designing heat exchangers, heat pumps, and PP-R pipes as a single, holistic solution creates an efficient, durable, and leak-free system. This transforms the data centre into an energy hub, making its waste heat systematically usable.

1. Heat exchanger – interface between IT and network
   A double-redundant plate heat exchanger is installed on the rack cooling circuit. It decouples the sensitive primary circuit from the downstream heating network, prevents contamination, and allows maintenance during operation. Modern stainless steel plates achieve dwell times of less than 30 seconds, keeping flow resistance so low that the IT pumps require minimal additional power. Heat exchangers are essential for transferring thermal energy efficiently from the data centre to the heating grid.
   
   
2. Heat pumps – temperature increase of 30 to 40 K
   Cooling water from air or water cooled servers typically leaves the data centre at 35-50 ° Two-stage industrial heat pumps using low-GWP refrigerants efficiently raise this to 80-85 °C – ideal for modern low-temperature district heating networks. Field measurements show COP values of up to 4.2 and energy recovery rates of around 40% in large-scale systems, making heat pumps a key technology for effective waste heat utilisation.
   
   
3. Pipe systems – the silent cash cow
   Pipes have the longest lifecycle of all components. PP-R pipe systems, such as aquatherm blue, are made of glass fibre-reinforced polypropylene. They are corrosion-free, approximately 80% lighter than steel, and joined using hot-melt fusion, which creates a perfect bond and minimises leak risk. Manufacturer tests and independent reports certify a service life exceeding 50 years. The smooth inner surface (roughness < 0.007 mm) reduces pumping work and operational expenditure (OPEX), making these pipes critical for low-loss heat transfer.
   
   
4. Grid connection – proximity beats size
   Shorter pipe routes improve the business case. Practical projects demonstrate that distances of less than two kilometres – for example, from a hyperscale data centre to an adjacent residential area – can reduce heat production costs by up to 25%. The European standard EN 12828 recommends planning connection points for future heat consumers early in the design phase and designing pressure maintenance systems to allow network expansions without complete shutdowns. Minimising distance is therefore a key factor in the economic efficiency of waste heat utilisation.
   
   
5. District heating – turning excess heat into energy supply
   The waste heat from data centres can also be used to supply district heating networks. For the reliable transfer of the water heated by waste heat, aquatherm offers an innovative piping system: aquatherm energy. The system consists of pre-insulated polypropylene pipes with a three-layer structure: a PP-RCT carrier pipe, PUR foam insulation, and an HDPE outer jacket. This design maximises energy efficiency, minimises heat loss, and provides high chemical and thermal resistance. aquatherm energy pipes are lightweight, flexible, and easy to install, making them ideal for extensive underground networks. Their robust construction and corrosion resistance guarantee long-term operational reliability for municipalities, utilities, and building complexes, supporting sustainable and future-proof heating solutions for neighbourhoods and entire cities.

Legal requirements and funding opportunities

The political climate is rapidly shifting towards the mandatory recovery and utilisation of waste heat from data centres.
Anyone planning projects today should be aware of the relevant guidelines and actively incorporate them into the business case.

Europe sets the legal framework

With the revised EU Energy Efficiency Directive (EU/2023/1791), new rules will apply to data centres above 1 MW from October 2025: operators must technically assess the possibility of waste heat utilisation, submit a cost-benefit analysis, and report key data (including PUE and heat extraction) to an EU database annually.

Supported by strong policy and funding

Governments and utilities are backing the next wave of heat-recovery infrastructure.