What WarmteStad does

WarmteStad is a publicly-owned district heating and cooling utility serving the city of Groningen, Netherlands. Founded in 2014 by the municipality of Groningen and Waterbedrijf Groningen, it became 100% municipally owned in September 2025 and operates without a commercial profit motive, reinvesting all surplus into the public heat network. The company delivers sustainable heat to approximately 10,000 homes and buildings (~40 GWh/year, over 10% of city demand) and is targeting 65% city coverage, with 11,000 connections planned in the northwest by 2027.

Its core technology stack integrates three sustainable heat sources — datacenter waste heat (QTS and Eurofiber), large-scale solar thermal collection at the 37,000 m² Zonnewarmtepark Dorkwerd, and Aquifer Thermal Energy Storage (ATES/WKO) wells at ~175m depth holding up to 230M liters of seasonal thermal storage — combined with large-scale heat pumps and cogeneration at the WarmteCentrale Zernike (opened 2022, 12,500-household capacity). A Gradyent Digital Twin continuously optimizes production, supply temperatures, heat-pump COP and electricity-market responsiveness, recognized internationally at the Global District Energy Climate Awards 2026.

WarmteStad's business model is a regulated subscription utility: customers pay a monthly advance (voorschot) covering fixed costs (meter/delivery-set rental, capped at €615.66 for 2026) plus variable usage priced per gigajoule (€38.92/GJ in 2026, 5% below the ACM ceiling of €40.97/GJ). GTM is field-driven and partnership-anchored — four housing corporations (Lefier, Nijestee, Patrimonium, De Huismeesters) act as the primary residential channel, with weekly neighborhood walk-in offices (spreekuren) and the MijnWarmteStad self-service portal supporting end customers. Institutional anchors include RUG (Zernike Campus, 9 buildings + 3 tennis halls), Hanzehogeschool Groningen, and commercial operators such as Brivec BV.

Name

WarmteStad

Legal name

WarmteStad

Website

https://warmtestad.nl

Company type

Private

Founded year

2014

Operating status

Operating

Headcount range

51–100 employees

Short description

WarmteStad is a publicly-owned (Municipality of Groningen) district heating and cooling utility serving ~10,000 Groningen homes and buildings with renewable heat sourced from solar thermal, datacenter waste heat and ATES, operating as a regulated non-profit subscription utility.

Ownership category

akta.pro rank

Product category

District Heating Services

NAICS

Steam and Air-Conditioning Supply (221330), Steam and Air-Conditioning Supply (22133)

SIC

Steam & Air-Conditioning Supply (4961), Cogeneration Services & Small Power Producers (4991)

akta.pro primary industry

District Heating & Cooling Thermal Storage (Network-Integrated TES) (EUAFANAH)

akta.pro secondary industries

Heat Pumps (Air/Water/Ground Source) (IMAHAKAF), Waste Heat Recovery & Heat Integration (HRSG/ORC, Pinch Analysis, Heat Exchangers) (EUABAJAF)

Keywords

• District heating services
• Renewable heat supply
• Thermal energy storage
• Sustainable heat network
• Heat and cooling utility

Headquarters

HQ city

Groningen

HQ country

Netherlands

HQ region

Europe

Offices5 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Infrastructure, Technology or R&D, Operations, Personnel, Supply Chain

Revenue model

1. District Heating Supply: WarmteStad generates revenue through regulated district heating tariffs charged to connected homes and buildings. Customers pay a monthly advance payment (voorschot) covering fixed costs and estimated consumption, with annual reconciliation. Revenue is non-profit by mandate, with all surplus reinvested in the network. Fixed costs include heat meter rental, delivery costs, and delivery set (afleverset) rental. Variable costs are measured in gigajoules (GJ).
2. WKO (Heat and Cold Storage) Services: Warmte- en Koudeopslag (ATES) services for new buildings, supplying both heating and active cooling through seasonal underground thermal storage. Revenue generated through connection and service fees for WKO-connected properties.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels8 records

Core offering

WarmteStad operates a sustainable district heating network (warmtenet) and aquifer thermal energy storage (WKO) systems in Groningen, Netherlands, delivering renewable heat, hot water, and active cooling to homes and buildings. Heat is sourced from local sustainable resources including solar thermal collection, datacenter waste heat (QTS, Eurofiber), and large-scale heat pumps, and is distributed through a physical pipeline network under regulated tariffs 5% below the ACM maximum rate.

Product overview

WarmteStad offers a portfolio of sustainable heating and cooling solutions for the city of Groningen. The core offerings consist of the Warmtenet (District Heating Network), which delivers renewable heat sourced from solar warmth, data center residual heat, and large-scale heat pumps, and the Warmte- en Koudeopslag (WKO) system, which uses subsurface groundwater storage for seasonal heat/cold cycling. These are complemented by the MijnWarmteStad customer portal for self-service account management. The company operates as a public utility without commercial profit motives, providing fair pricing regulated by the ACM (Autoriteit Consument & Markt).

Differentiator

Problem solved

Functional benefit

Products and services

• Warmtenet (District Heating Network) A sustainable district heating network that delivers renewable heat and hot water to homes and buildings in Groningen, using local sources such as solar warmth, residual heat from data centers, and heat pumps. Customers pay regulated tariffs 5% below the ACM maximum rate under the Niet Meer Dan Anders (NMDA) principle.
• Warmte- en Koudeopslag (WKO) - Heat and Cold Storage A subsurface energy storage system that stores excess summer heat in groundwater aquifers for use during winter, and vice versa, providing both sustainable heating and active cooling for new and existing buildings. WKO services are offered to new construction projects (e.g., De Suikerzijde, Tender, Borchrijck) and are integrated into the building design from the start.

Quantifiable outcome

• 50% CO₂ reduction since 2022 (WarmteCentrale Zernike)
• +6 more outcomes

Named customers8 records

Segments4 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Ten partnerships are on record, tiered core and minor.

• Rijksuniversiteit Groningen (RUG)coreStrategic or Co-development Partner · 11 February 2025RUG is connecting 9 buildings and 3 tennis halls at Zernike Campus to WarmteStad's district heating network over two years. The connection saves 3 million kg CO₂ annually. WarmteStad provides sustainable heat sourced from datacenter waste heat and solar thermal. The RUG's total CO₂ footprint was 34 million kg in 2023, with gas representing 19%. This connection halves that share.
• Lefier, Nijestee, Patrimonium, De HuismeesterscoreStrategic or Co-development Partner · 11 October 2024Four major Groningen housing corporations signed an addendum with WarmteStad to connect an additional 2,000 rental homes to the district heating network by end of 2026. Properties are in the northwest neighborhoods Kostverloren, Paddepoel, Selwerd, and Vinkhuizen. The partnership leverages the €22M Nationaal Groeifonds subsidy to reduce connection costs for housing corporations and their tenants.
• Novar, K3, TVP SolarcoreTechnology or Integration · 15 May 2024Developer consortium and technology partner for Zonnewarmtepark Dorkwerd, the largest solar thermal park in the Netherlands. Novar and K3 developed the park; TVP Solar provided vacuum tube collector technology. The park covers 37,000 m² and has been operational since 2024, supplying solar thermal heat to WarmteStad's network.
• GradyentcoreTechnology or Integration · 1 January 2024Gradyent provides Digital Twin software that creates a digital replica of WarmteStad's heat systems, enabling continuous optimization. The software improves production efficiency, optimizes supply temperatures, reduces heat losses, maximizes heat pump COP, and adapts to electricity market fluctuations. This partnership was recognized with an international Certificate of Merit at the Global District Energy Climate Awards 2026.
• Grunneger PowerminorStrategic or Co-development PartnerLocal energy cooperative that supports homeowners in the Groningen heat transition, providing advice and coordination for private homeowners (VvE's) considering connection to the district heating network.
• QTS (datacenter)coreTechnology or IntegrationQTS datacenter supplies waste heat from its operations to WarmteStad's district heating network, which is then distributed to homes and buildings in Groningen. This is one of the primary sustainable heat sources for the network.
• Eurofiber (datacenter)coreTechnology or IntegrationEurofiber datacenter provides additional waste heat to WarmteStad's network, complementing the QTS datacenter waste heat supply. The expansion of waste heat sourcing from Eurofiber is part of network growth.
• EnexisminorStrategic or Co-development PartnerEnergy grid operator collaborating with WarmteStad, the municipality, housing corporations, and Grunneger Power on neighborhood-level sustainability projects such as the Vinkhuizen energy plan.
• EnergiewachtminorImplementation/ SI/ Consulting PartnerService partner providing 24/7 emergency response for heat network outages and malfunctions. WarmteStad refers customers experiencing service issues to Energiewacht outside of business hours.
• Hanzehogeschool GroningencoreStrategic or Co-development PartnerHanzehogeschool leads the 'Future Heat Heroes' consortium, awarded a European Green Deal subsidy for developing 5th generation heat networks. A test installation will be connected to WarmteStad's network at Entrance on Zernike Campus, creating a unique real-world research environment. Partners include Alfa-college, Witteveen+Bos, and Oosterhof Holman.

Scale indicators9 records

Recent moves7 records

Expansion highlights6 records

Others

• QTS Realty Trust (datacenter / GIC portfolio):
• Gradyent: Gradyent is the software vendor whose Digital Twin platform WarmteStad uses to optimize its network. While not a direct competitor, Gradyent is a strategic technology partner and ecosystem participant — other utilities using Gradyent represent the closest cluster of digitally-advanced district heating peers, and Gradyent's footprint indicates which other networks are pursuing similar optimization strategies.

Direct peers

• Ennatuurlijk: Ennatuurlijk is a Dutch district heating operator serving multiple regions and cities with sustainable heat networks for residential and business customers. As a directly comparable peer operating network-integrated heating with similar regulated tariff structures and a focus on decarbonization, Ennatuurlijk is the closest single-country, multi-city equivalent to WarmteStad.

Regional players

• HVC: HVC is a Dutch public waste and energy company owned by municipalities and water authorities, operating waste-to-energy plants and supplying heat to networks in North Holland and South Holland regions. Comparable to WarmteStad in its public-utility ownership structure, regulated tariff discipline, and focus on municipal decarbonization, though HVC's primary business is waste processing with heat as a by-product.
• Stadsverwarming Purmerend: Stadsverwarming Purmerend is a regional Dutch district heating utility serving a single Dutch city with sustainable heat. As a similarly-sized single-city peer, it is directly comparable to WarmteStad in scale, customer base (~10k+ connections), and public-utility operating model.
• Mainova (N-ERGIE / Mainova Wärme): Mainova operates district heating networks primarily in Frankfurt, Germany, with comparable ATES, heat pump, and waste-heat integration. As a German regional peer, Mainova is a useful international benchmark for the economics of municipal district heating utilities in the broader DACH region.

Broad incumbents

• Fernwärme Wien (Wien Energie): Wien Energie's Fernwärme Wien is one of Europe's largest municipal district heating utilities, serving over 400,000 Vienna households with a mix of waste-heat, CHP, and renewable heat. It is a broad incumbent benchmark for what a fully-scaled, municipally-owned district heating operation can become — relevant for understanding WarmteStad's long-term growth ceiling.
• ENGIE (Cofely / ENGIE Nederland): ENGIE operates Dutch district heating and cooling networks and provides municipal-scale heating infrastructure solutions across the country. Comparable to WarmteStad in deploying ATES, large heat pumps, and residual heat recovery for urban networks, though ENGIE is part of a global utility with significantly broader scope and resources.
• Vattenfall (Nuon Warmte): Vattenfall's Dutch arm (formerly Nuon) operates large district heating networks in Amsterdam, Utrecht, and Almere, serving tens of thousands of households with a mix of residual and renewable heat. It is a broad incumbent peer with comparable district heating infrastructure, ATES/WKO usage, and customer base, but at substantially larger scale and serving multiple Dutch cities.
• Eneco: Eneco is one of the largest Dutch energy utilities, operating district heating networks in multiple cities (e.g., Rotterdam, Utrecht, Den Haag) and offering sustainable heat solutions at scale. As a broad incumbent in the same product category (district heating for residential/utility customers), Eneco is the most relevant comparison point for WarmteStad's network economics, though Eneco is for-profit and serves a much larger, multi-city footprint.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/warmtestad
• Facebookfacebook.com/WarmteStadGroningen
• LinkedInlinkedin.com/company/warmtestad

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about WarmteStad