Wien Energie GmbH is the largest regional energy provider in Austria, supplying approximately two million customers with electricity, heating, cooling, electromobility, and telecommunications services. The company operates primarily in Vienna and the surrounding Lower Austria region. It is a wholly owned subsidiary of Wiener Stadtwerke GmbH.
Connect with Fabian Kasicki on LinkedIn here.
00:02 Introduction & About Wien Energie03:55 Why Wien Energie Partners with Startups08:53 How Wien Energie Prepares Startups to Understand Their Problems10:34 Success Story: Kauz AI & the Digital Product Advisor11:54 The Pilot Process: Structure & Timeline14:37 Getting Top Management Buy-In for Scale16:09 Startup Positioning Tips: How to Get Beyond Pilot17:34 Success Story: Kraken & Sustainable Procurement20:56 Tips for Preparing RFPs — Tecloman Case Study22:12 Wien Energie’s Four Innovation Focus Areas23:23 Active Searches: EV Charging AI & Solar Forecasting24:54 Biggest Unmet Opportunities in the Energy Ecosystem26:41 Advice for Early-Stage Companies Entering the Utility Space
Check out our companion episode with Tecloman, a scaleup working with Wien Energie!
The Heat Beneath the Surface: Why District Cooling & Heating Is the Startup Opportunity DACH Utilities Are Waiting For
Vienna sits atop one of Europe’s most sophisticated thermal networks. Wien Energie operates the fifth largest district heating grid and the fourth largest district cooling grid in the entire European Union, serving millions of residents and businesses, fed partly by waste incineration plants that thermally treat roughly every fourth ton of waste generated in Austria.
Yet for all its scale, the network is at an inflection point.
In a recent conversation on the Klimatic Scale podcast, Fabian Kesicki, Head of Corporate Development at Wien Energie, named decarbonized and flexible district energy systems as one of the utility’s four core innovation focus areas. “We have very large district cooling and heating systems and we see big potential there,” he said, “particularly in the direction of decarbonized systems and flexible systems.”
For startups working at the intersection of thermal infrastructure and clean technology, this signals something important: the demand is real, the budgets exist, and the utilities are actively looking.
Why District Cooling & Heating Is Having Its Moment
District energy, the centralized production and distribution of heating and cooling through underground pipe networks, is among the most overlooked levers in Europe’s decarbonization toolkit. Unlike rooftop solar or EV charging, it operates largely out of sight, which has kept it out of the startup conversation. That is changing fast, for three reasons.
1. The gas transition is creating a strategic gap.
Most large DACH utilities still rely on gas-fired combined heat and power (CHP) plants as the backbone of their district heating systems. As gas becomes economically and politically untenable, these utilities face an urgent need to replace gigawatts of thermal capacity with alternatives: heat pumps drawing from rivers and aquifers, geothermal, industrial waste heat, and seasonal thermal storage. The technical complexity of this transition, and the speed at which it needs to happen, is far beyond what utility R&D teams can handle alone.
2. Cooling demand is surging.
Central European cities were not designed for the temperatures they are now experiencing, especially experienced in the recent May 2026 heatwave where temperatures soared above 35 C. Vienna, Munich, Zurich, and Frankfurt are all investing heavily in district cooling capacity as the climate forces the issue. Wien Energie’s fourth-place EU ranking in district cooling is not a legacy position, it reflects years of deliberate investment. Across DACH, that investment is accelerating, and startups with solutions for efficient, low-carbon chilled water distribution, thermal storage, and demand-side management have a growing market.
3. The grid flexibility imperative.
One of the most compelling dynamics Fabian highlighted is the growing frequency of negative electricity price hours across European markets, periods when supply from renewables exceeds demand and prices turn negative. District heating and cooling systems, with their large thermal mass, are natural flexibility assets: they can absorb excess electricity (via heat pumps or electric boilers), store it as heat or cold, and dispatch it later.
“Using the flexibility potential of the heating sector is where we can still use some innovative ideas.”
This positions district energy squarely within the broader energy system flexibility story, and opens a substantial commercial opportunity for startups that can help utilities unlock that value.
What DACH Utilities Actually Need
Based on what Wien Energie and similar utilities in Germany, Austria, and Switzerland are signaling, the most relevant startup categories for district cooling and heating break into several clusters:
Decarbonization of heat sources. Replacing gas-fired generation with scalable, dispatchable alternatives. This includes large-scale heat pump technology adapted for utility-grade applications, aquifer thermal energy storage (ATES), deep geothermal, and industrial waste heat recovery. The challenge is not just the technology itself but integration with existing grid infrastructure, and managing the transition without compromising reliability.
Grid intelligence and digital twins. Aging district energy networks were built before sensors were cheap and before machine learning existed. Startups offering real-time network monitoring, predictive maintenance, leak detection, and digital twin platforms find a receptive audience at utilities struggling to optimize grids that span hundreds of kilometers of underground pipe. The ability to ingest SCADA data, model thermal behavior, and surface actionable insights is in high demand.
Demand-side flexibility and virtual thermal storage. Rather than building new physical storage, some of the most capital-efficient flexibility solutions exploit the thermal inertia that already exists in buildings connected to district networks. Startups with software that can coordinate building-level setpoints, hot water buffer tanks, and process heat loads to shift demand in real time, without degrading comfort, offer utilities a low-cost flexibility tool that complements generation-side assets.
Seasonal thermal energy storage. For utilities with significant renewable heat sources (solar thermal, industrial waste heat), the mismatch between summer supply and winter demand is a persistent challenge. Pit thermal energy storage, borehole storage, and aquifer systems are gaining traction, but the planning, permitting, and optimization software to make these projects viable at scale remains underdeveloped.
Cooling-as-a-service and building integration. On the cooling side, the interface between district networks and commercial buildings is surprisingly manual and inefficient. Startups that can automate substations, optimize heat exchanger performance, and offer data-driven service models to building operators are addressing a gap that utilities recognize but have limited capacity to fill internally.
How to Actually Work With a DACH Utility
Understanding the opportunity is one thing. Navigating the path from first conversation to signed contract is another. Fabian was refreshingly candid about what the process looks like from the utility side, and the lessons apply broadly across DACH.
Start with the problem, not the product. The single quality that separates shortlisted startups from the rest, according to Fabian, is whether they have genuinely understood the utility’s challenge. “Is it just a standard slide deck, or have they understood what is the challenge that Wien Energie faces in this business unit?” Generic pitches do not advance. Problem-specific proposals, shaped by reading public materials and asking direct questions, do.
Know that pilots run six to twelve months. Wien Energie’s standard pilot structure involves a shared problem definition, agreed KPIs, and a contractual framework established before work begins. Startups that push to skip the paperwork and “just start” create friction that slows everything down later. Embrace the process.
Secure the department head, not just the innovation team. Wien Energie’s scaling decision requires an explicit commitment from the relevant department head, not just internal champions in the innovation group. The implication for startups is to make sure your solution addresses a problem that the business unit owner cares about, not just something the innovation team finds intellectually interesting. The innovation team’s job is to translate; your job is to give them something worth translating.
Prepare for procurement reality. Once a pilot succeeds and a longer-term collaboration is on the table, a formal tender process typically follows. Startups that understand this, prepare their documentation early, and are willing to navigate the process (often partly in German) are far better positioned than those who treat it as an obstacle.
Build relationships before you need them. Wien Energie runs its innovation process through a structured program (the Climate Lab, in partnership with Impact Hub Vienna) and publishes its challenge topics openly. The same pattern: open calls, published problem statements, multi-stage evaluation, applies across most major DACH utilities. Following these programs, engaging early, and showing up at industry events before an active procurement process is the most reliable way to be in the room when decisions are made.
The DACH Landscape: Structural Advantages for Startups
Beyond Wien Energie, the DACH region has structural characteristics that make it an unusually strong market for district energy startups.
Germany has set binding targets for district heat to cover 50% of national heat demand by 2045 and has passed the Wärmeplanungsgesetz (Heat Planning Act), requiring municipalities above 100,000 residents to publish heat transition roadmaps by mid-2026. This creates a procurement wave that is just beginning.
Austria has committed to phasing out oil and gas heating, and its alpine geography makes it an interesting testbed for combinations of hydropower, geothermal, and seasonal storage. Several Austrian Stadtwerke (municipal utilities) beyond Wien Energie are actively investing in network expansion and decarbonization.
Switzerland, with its high energy costs and strong industrial base, offers particularly interesting opportunities in industrial waste heat recovery and premium district cooling for data centers — a fast-growing load in the arc from Zurich to Geneva.
Across all three countries, the utility landscape is dominated by municipal players with long investment horizons, genuine sustainability mandates, and critically the balance sheets to pay for solutions that work. The market rewards startups that can demonstrate reliability and integration competence, not just novelty.
The Window Is Open
District cooling and heating is not a glamorous sector. It does not have the consumer visibility of EVs or the narrative heat of green hydrogen. But it is one of the largest addressable markets in the European energy transition, it is controlled by utilities that are actively seeking startup partners, and the technical problems are genuinely hard — which means the competitive field is less crowded than it should be.
Fabian’s closing advice to early-stage companies was simple: understand the problem deeply, bring a concrete use case, play the long game, and invest in the relationship before expecting a return. “It’s about building relations,” he said. “Just bring this understanding to the table that it will take time.”
For startups willing to do that work, the thermal networks under Europe’s cities represent one of the most durable opportunities in climate technology.
This article was informed by the Klimatic Scale podcast episode with Fabian Kesicki, Head of Corporate Development at Wien Energie. Klimatic Group works with climate-focused startups and utilities across the DACH region.
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