The transition towards low-carbon thermal energy systems requires solid information provision to support both public and private decision-making, which is future proof and optimal in the context of the system dependencies. We adopt a data ecosystem approach to answer the following research question: How can a data ecosystem be analyzed and developed to enable the data-driven support of the local thermal energy transition, by capturing both social and technical aspects of the urban thermal energy system? A case study research design of the Netherlands, with an embedded case of the city of Utrecht therein, was used, including data collection involving 21 expert interviews representing a diversity of stakeholders, and qualitative data analysis using NVivo version 10. The data ecosystem includes the necessary elements, roles, and context for decision makers in a local heat transition and captures the social as well as technical aspects of an urban thermal energy system. Assessment of the data ecosystem pertaining to thermal heat transition in the city of Utrecht shows that it is still in its infancy phase, with challenges, barriers, and shortcomings in all its key elements. We present suggestions for the (re-)design of an inclusive and holistic data ecosystem that addresses the current shortcomings.

In 2018, the Dutch national government announced its decision to end natural gas extraction. This decision posed a challenge for local governments (municipalities); they have to organise a heat supply that is natural gas-free. Energy models can decrease the complexity of this challenge, but some challenges hinder their effective use in decision-making. The main research question of this paper is: What are the perceived advantages and limitations of energy models used by municipalities within their data-driven decision-making process concerning the natural-gas free heating transition? To answer this question, literature on energy models, data-driven policy design and modelling practices were reviewed, and based on this, nine propositions were formulated. The propositions were tested by reflecting on data from case studies of ten municipalities, including 21 experts interviews. Results show that all municipalities investigated, use or are planning to use modelling studies to develop planning documents of their own, and that more than half of the municipalities use modelling studies at some point in their local heating projects. Perceived advantages of using energy models were that the modelling process provides perspective for action, financial and socio-economic insights, transparency and legitimacy and means to start useful discussions. Perceived limitations include that models and modelling results were considered too abstract for analysis of local circumstances, not user-friendly and highly complex. All municipalities using modelling studies were found to hire external expertise, indicating that the knowledge and skill level that municipal officials have is insufficient to model independently.