Powering the energy transition at the district level_Cities4PEDs_AWB_final

Is the Northern Quarter in Brussels representative of other
districts? Yes and no. Yes because none of the six experiments in Chapter 1
achieves a ‘positive energy balance’, not even in the most ambitious scenario.
No because the Northern Quarter is a particularly dense district with comparatively
little roof area and a very high energy demand. In general, it is more
difficult, if not impossible, for high-density districts to achieve a positive energy
balance. But density isn’t the only factor. The presence of many buildings
with heritage value implies that the thorough insulation of façades is impossible.
Buildings in existing neighbourhoods may also have a particular orientation or
roof shape that can’t be changed to accommodate PV panels. In many existing
districts or brownfields, the subsoil is already full of pipes and cables, meaning
that new energy infrastructure has to find a place for itself. Taking all these
specificities into account, we understand that different neighbourhoods can’t
produce the same amount of energy. Nor will every neighbourhood achieve the
same building performance. It therefore makes little sense to opt for a generic
target that fails to take these specificities into account. In conclusion, different
contextual reasons help to explain why none of the six districts achieves a
positive energy balance.
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And yet we want all these districts to become PEDs: they
should do their maximum and fair share, so that the target for the regional
energy balance can be reached. But how are we to calculate that share? A
positive energy balance doesn’t work as an absolute and generic target for all
districts. We therefore propose to aim for a ‘relative positive energy balance’,
one in which the specificities of each context are taken into account via a set
of contextual parameters. These factors help to determine the specific ‘head
start’ for a dense neighbourhood, compared to another target in a greener
neighbourhood, for example. What context factors are considered, and how,
is the subject of ongoing research. One way of accounting for them is using a
quantitative method of calculation. Based on the first PED simulations and
real-life results, researchers are identifying patterns and translating them
into a standard calculation method for context factors. Concrete tests should
show whether it suffices to capture the complex reality of each neighbourhood
in numbers (alone). In addition to a fully quantitative calculation method,
qualitative assessment methods might have to be developed to determine the
contextual differences between neighbourhoods (and their impact on the share
these districts should do in the energy transition).
In the paper ‘A Quantitative Positive Energy District
Definition with Contextual Targets’, the Fachhochschule Technikum Wien
(Vienna polytechnic university) tested two aspects of a quantitative calculation
model for the PED energy target (Schneider et al., 2023). On the one hand, it
defines a context factor for density, based on test cases in Austria, Belgium and
Sweden. The graph on the next page shows the curve representing the relative
positive energy balance when this context factor for neighbourhood density is
taken into account. Low density neighbourhoods (