Cities play a key role in driving the transition to sustainable energy. Urban areas represent between 60% and 80% of global energy consumption and are a significant source of CO₂ emissions, making energy management at the urban scale an important area of research. Urban energy systems have a strong influence on the environment, economy, social dimensions and urban spatial planning. Energy consumption affects the urban microclimate, urban comfort, human health, and conversely, urban physical, economic and social characteristics affect the energy urban profile. In order to improve the quality of energy strategies, policies, and plans, local authorities need decision support tools, like energy potential mapping, which have risen significance in the last decades. Energy data are crucial for those tools. They can increase the quality and effectiveness of energy planning but also support the integration between energy and spatial planning. Energy data can also stimulate citizen engagement as well as encourage sustainable behaviours and CO₂ emission reduction. This paper aims to increase the practice of data-aware planning, through the study of problems in energy data acquisition and processing observed in European projects focused on developing energy mapping tools. The problems observed attend to two main areas: technical and socio-economic issues. Those were derived from a comparison of energy mapping tools, and the work conducted for the PLANHEAT development. The scope of the research is to understand the main recurring issues in energy data acquisition and processing, in order to overcome the barriers in data availability. Increasing awareness of the relevance of energy data can foster the use of energy mapping tools, increasing the quality of energy policies and planning.

It is difficult to fully satisfy the energy demand of today’s society with renewables. Nevertheless, most of the energy we use is lost as non-functional waste energy, whereas a large part of the built environment’s energy demand is only for low-quality energy, so the initial demand for primary, high-quality energy can be reduced by more effective usage, such as by low-exergy means. Gaining insight into the parameters of energy demands and local renewable and residual energy potentials enables matching energy demand with a fitting potential, not only concerning quantity but taking into account location, temporality and quality as well. The method of Energy Potential Mapping (EPM) aims to visualise the energy potentials and demands by making information of quantity, quality and location of demand and supply accessible. The aspect of quality specifically applies to heat and cold. The methodology of EPM will be described and explained with case studies. The focus specifically lies on mapping heat (and cold), one of the main reasons for energy demand in the built environment. The visualisation of exergy, to be simplified as the quality of energy, becomes an extra parameter in the case of Dutch Heat Maps. These maps can help finding opportunities of practical implementations of exchanging or cascading heat or cold. This way EPM and Heat Mapping (HM) enables application of exergy principles in the built environment. EPM and HM can be seen as a local energy catalogue and can be useful in spatial planning for energy-based urban and rural plans.