A2A and Equinix have launched one of Europe's most ambitious heat-recovery operations outside Scandinavia, channeling excess warmth from digital servers into Milan's district heating grid and potentially raising the network's capacity by 20% — enough to heat over 21,000 homes while preventing 345,000 tonnes of CO₂ emissions annually.
Why This Matters:
• 225 GWh of thermal energy will be recovered yearly from the Equinix campus in Settimo Milanese, equivalent to the heating needs of a mid-sized Italian city district.
• The scheme will expand A2A's heating network to iconic landmarks including the Duomo and Palazzo Reale, marking a strategic shift from fossil-fuel boilers to circular digital infrastructure.
• This partnership represents a €72M investment in heat pumps and thermal storage, with a payback horizon estimated at 3 to 6 years — a rare intersection of environmental urgency and near-term profitability.
• Milan joins a small cohort of non-Nordic European cities — alongside Brunswick, Frankfurt, and Paris — converting server heat into municipal assets, while Italy trails Northern Europe in district heating penetration (under 5% of households compared to over 60% in Denmark).
What This Means for Residents
Anyone living or investing in Milan's urban fringe should expect gradual heating-network expansion over the next 24 months. The Energy Centre built by A2A near Settimo Milanese will house four industrial-scale heat pumps (72 MW combined) and two thermal reservoirs totaling 6,000 cubic meters — enough to stabilize supply during winter peaks. Renato Mazzoncini, CEO of A2A, framed the project as a necessary pivot: "Data centers are strategic infrastructure, and their growth requires models that marry technological innovation with energy efficiency and environmental sustainability."
For households in Municipio 6 and surrounding areas already connected to the A2A grid, the shift will be seamless — no new boilers, no retrofit costs. The recovered heat will blend into existing hot-water loops, replacing natural-gas-fired generation. Over the medium term, A2A plans to extend piping into the historic center, potentially connecting the Cathedral precinct and royal palace complex — a technical feat given the dense medieval street layout, but one that signals confidence in the model's scalability.
From Server Rack to Radiator
Equinix operates the export side: its engineers will design and manage the systems that capture exhaust heat from customer servers and pump it into insulated conduits bound for the A2A facility. Adaire Fox-Martin, CEO and President of Equinix, underscored the firm's intent to "align business needs with the communities hosting our infrastructure" — language that reflects growing pressure on hyperscale operators to offset their carbon footprint as global data-center electricity demand doubles by 2026, driven largely by artificial intelligence workloads.
Once the heat arrives at the Energy Centre, A2A's pumps will elevate its temperature to district-standard levels (typically 80°C to 90°C) before distribution. The thermal reservoirs act as buffers, absorbing excess capacity during low-demand periods and releasing it during morning and evening surges. This flexibility is critical in a city where winter heating accounts for a disproportionate share of residential energy use.
Italy's Emerging Heat-Recovery Landscape
The Equinix-A2A initiative is the largest but not the first of its kind on Italian soil. In June 2025, A2A inaugurated a Qarnot-designed data center in Brescia that uses advanced liquid cooling to recover heat at 65°C, feeding 16 GWh annually into the Lamarmora district network — sufficient for 1,350 apartments and abating 3,500 tonnes of CO₂. In Milan's Municipio 6, Retelit's Avalon 3 facility already supplies 15 GWh per year to 1,250 households, saving 1,300 tonnes of equivalent petroleum and cutting 3,300 tonnes of emissions. Near Rozzano, TIM Enterprise's data center will warm more than 5,000 ALER social-housing units via heat exchangers and pumps.
A joint Teha-A2A analysis suggests that connecting Italy's 168 operational data centers to district grids could avoid 2M tonnes of CO₂ yearly, rising to 5.7M tonnes if complementary efficiency measures are adopted nationwide. Yet less than 5% of Italian households accessed district heating as of 2022, compared to over 60% in Denmark and 50% in Sweden — a gap the government aims to close through PNRR (Piano Nazionale di Ripresa e Resilienza) incentives earmarked for low-carbon infrastructure.
How Europe Handles Server Heat
Northern Europe remains the undisputed leader. Microsoft's Høje-Taastrup data center near Copenhagen will heat 6,000 homes via the VEKS network when it completes construction, while Equinix's Helsinki campus already feeds the Helen utility's grid. In Stockholm, DigiPlex warms 10,000 modern apartments, and in Norway a trout farm run by Hima Seafood uses server exhaust to regulate fish-pond temperatures.
Germany's Energy Efficiency Act, effective since January 2024, mandates that new data centers achieve a 10% Energy Reuse Factor by mid-2026, climbing to 20% by 2028. Telehouse Germany in Frankfurt already channels 60% of its waste heat into the FRANKY residential quarter, and Brunswick's ReUseHeat project employs heat pumps to lift low-grade server warmth to district-standard temperatures.
France, meanwhile, is experimenting with unconventional sinks: the Butte-aux-Cailles swimming pool in Paris draws all its thermal energy from a basement server room, saving 45 tonnes of CO₂ annually, and Data4's Marcoussis campus at Université Paris-Saclay is piloting a "bio-circular" model that converts heat into algae biomass — capturing 36 kg of CO₂ daily and producing 20 kg of protein-rich biomass, with an absorption rate 20 times that of mature trees.
Economic and Environmental Returns
The Equinix-A2A collaboration pencils out on multiple fronts. District heating from recovered server warmth can deliver a payback window of three years for network operators, according to pilot studies, while tenant buildings eliminate natural-gas bills altogether. A POLITesi study calculated a six-year break-even for medium-scale commercial heat reuse, and the aggregate economic benefit of a national efficiency push — factoring in avoided fuel imports, carbon credits, and infrastructure productivity — could approach €1.7 billion, with a €55 billion contribution to GDP as digital and energy sectors converge.
From an emissions standpoint, replacing gas boilers with server heat removes a significant slice of Scope 1 and 2 carbon. The Avalon 3 project in Milan alone offsets the annual CO₂ sequestration of 24,000 trees, while the broader portfolio of Italian heat-recovery initiatives could theoretically satisfy the heating needs of 800,000 families — roughly one-tenth of the country's residential stock — if infrastructure buildout accelerates.
Challenges and Practical Hurdles
Heat recovery is not plug-and-play. Low-temperature exhaust (often 30°C to 50°C) requires large-scale heat pumps and electrical input to reach usable levels, raising questions about grid capacity in districts already strained by electric-vehicle uptake and induction cooking mandates. A2A's 72 MW pump installation is a direct response: the utility will draw power from renewable sources where possible, but the scheme's net carbon benefit hinges on the regional electricity mix.
Regulatory friction also looms. Italy's anti-discrimination statutes and energy-market rules were written for a pre-digital era, and adapting permitting frameworks to recognize data centers as "thermal generators" has required legal interpretation at both municipal and national levels. The PNRR unlocks capital, but execution depends on coordination among Equinix, A2A, municipal planning offices, and environmental agencies — a dance that historically proceeds slowly in Italy's bureaucratic landscape.
Finally, tenant agreements matter. Equinix cannot compel its colocation customers to retrofit servers with heat-export interfaces, so adoption remains voluntary and economically driven. If a critical mass of tenants declines participation, the 225 GWh target becomes aspirational rather than guaranteed.
What's Next
Construction of the Energy Centre is already underway, with phased commissioning expected through late 2026 and early 2027. A2A has signaled intent to replicate the model at other high-density data campuses in Lombardy, and industry observers anticipate similar announcements from hyperscalers operating in the Bologna-Florence corridor, where server capacity is expanding rapidly to serve Southern European markets.
For residents and commercial tenants in Milan, the immediate takeaway is practical: if your building sits within or near the current A2A district-heating footprint, inquire about connection timelines and potential cost savings. The utility's customer portal now includes a heat-network coverage map, updated quarterly, and a calculator estimating annual gas-bill reductions based on square meters heated.
For policymakers and investors, the Equinix-A2A venture offers a repeatable template — contingent on upfront capital, regulatory alignment, and willingness to view digital infrastructure not as a burden on the grid but as a distributed thermal asset. Whether that mindset takes root beyond Lombardy will determine if Italy closes the district-heating gap or remains an outlier in Europe's decarbonization race.
