Local stakeholders are interested in natural locational constraints, but also are planners who relate their design on locational constraints such as climate data on wind access, solar radiation, air-temperature distribution and time series, and water (and wind) temperatures.
The distribution system and storage constraints are mostly important to local maintenance staff and facility managers, but larger thermal storages equipment could be visible and important for inhabitants as well. Also, the level of noise of the distribution system could be of interest to inhabitants and users in the neighborhood.
When it comes to the building and facility, there are planners and architects involved. The end users or inhabitants play a limited role because they are often unknown and therefore categorized (according to building typology and use of the facility). Here, building codes have the role of defining the minimum requirements that would ensure comfortable use of the building. Involvement of planners and architects is normal, even more so in the next set of constraints that in particular is concerned with the indoor environment. Again, minimum requirements are established through building codes and standards. The building owner can decide on the level of indoor comfort, typically choosing between different levels/classifications (low, medium, high).
When it comes to the equipment in buildings and district systems, the technical functionality is defined in building codes and related standards. Planners and architects have the expertise to define them. However, some technologies can be chosen by the building owner or investor, e.g., if the building shall have a certain heating technology or specific façade technology.
There are different levels for applying EMP within an urban context: starting from the city level, followed by the neighborhood and then the group of buildings with their building regulations. The stakeholders involved can be framed into different categories as illustrated in Fig. 1.
Ideally, the potential reduction goals should be discussed on different levels with the relevant stakeholders in various constellations. A stakeholder forum would encourage a top-down approach, however, in some cases, a bottom-up approach seems more promising. There is the intrinsic problem that different stakeholder perspectives may result in an unclear nature of the problem since stakeholders at different levels view the problem differently. Architects and planners must rethink buildings and spaces; public authorities need to adapt organization and procedures; lawyers need to adapt legal and policy adaptation, etc. This can cause a lack of a unique problem statement and the choice of inadequate solutions for emission reduction.
Figure 2 illustrates the model by visualizing the boundaries in EMP by diagramming the top-down and bottom-up approaches for EMP on a neighborhood level. There are constraints coming from the building level, as well as from the regional level that will limit the technical possible solutions for a site-specific EMP. Various valid objectives possibly conflicting on short-to-medium terms require prioritizing (carbon-free cities; cheap affordable energy for all; regional energy self-sufficiency; job promoting energy system; fully renewable energy sources; etc.). This problem is intensified by the dynamic nature of energy planning parameters (energy price fluctuation; evolving new technologies; population growth; high urbanization rates; changing political actors and agendas etc.).
The quality of physical data is often not available, hindered by privacy and/or measurability issues. This aspect is enhanced by a vast set of technology options, uncertainties on effectiveness, and constantly evolving new solutions at different technological readiness levels.
While locational threats usually do not influence technology selections, locational resource limits, as well as the limits of existing distribution and energy storage systems, can profoundly affect technology selection.
Ambiguity in purpose leads to a lack of clarity about successful outcomes. This may lead to conflicting objectives. On the other hand, ambiguity in values prevents the clear assessment of outcomes. Different stakeholders will value sustainability criteria differently depending on their objective (societal benefits of clean energy opposed to the need for low investment costs, the “landlord- tenant” dilemma; top-down planning or bottom-up collaborative planning; etc.). Therefore, it is important that key performance indicators are introduced and that their weighted values are agreed upon at the beginning of the process.
Identified framing constraints should be evaluated as either a hard or soft constraint. If not, constraints that can be overcome may be missed and promising technologies stripped out of a final EMP solution.
On the political level, we find often unclear policy responsibilities and ambiguous values to address climate change, as well as disagreement on societal effectiveness of climate change policy. This is enhanced on the administrative level with ill-defined responsibilities, budgets and implementation procedures, no established standardized way on the definition and the monitoring and reporting of key performance indicators. On top of this, governments need to reach sustainability targets and safeguard public interest, while energy providers need to make profits and individuals need to reduce expenses.