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ZEB
annual report 2015
The integration of solar systems on a
building or district scale, producing energy
covering the demand of the buildings, is
becoming a priority in the urban planning
process. However, despite solar radiation
being sufficient, especially in southern and
central parts of Norway (annual horizontal
insolation around 900 kWh/m
2
in Grimstad),
the electricity production from solar energy is
still not significant. The difficulties are mostly
related to unpredictability and unreliability.
Therefore, new approaches for better
integration of solar systems into the building
envelope and preliminary evaluation of the
energy use should increasingly be taken into
consideration in the early design phases
during urban planning processes.
The continuous development of the city of
Trondheim due to the increase in population
has generated a further need for residential
buildings. The Norwegian Statistics Centre
(SSB) has estimated that from 2000 to 2030,
there will be an increase of 70 000 inhabitants.
In this framework, the area of Øvre Rotvoll,
connecting downtown Trondheim with the
residential neighbourhoods of Charlottenlund
and Ranheim, has the ambition to become
a development area designed according
to the targets of the Net-Zero Energy
Neighbourhood. This case study is framed
within the Subtask C
“Case studies and action
research”
of Task 51
“Solar Energy in Urban
Planning”
initiated by IEA’s Solar Heating and
Cooling Programme. The scope of the case
study was twofold: on the one hand, the aim
was to develop a solar potential analysis of
the district in order to maximize both passive
and active design strategies, and, on the other
hand, to achieve the energy target of the Net
Zero Energy Neighbourhood.
In the solar potential analysis, solar
dynamic simulations, using a RADIANCE
based software,
DIVA for Rhino,
has been
conducted. The results demonstrated how the
optimization of the buildings’ orientation, their
relative distances regulated by the aspect ratio
between the height (h) of the buildings and
width (w) of the street, and the use of finishing
materials on the façades and on the ground
could consistently affect the solar accessibility
of the buildings.
Based on the outcomes of a parametric study,
in which different aspect ratios (h/w=0.5, 1, 1.5
and 2), colours, and finishing materials for the
ground and façades, the entire masterplan for
the Øvre Rotvoll district has been developed.
The analyses conducted allowed minimizing
as much as possible the overshadowing
effect created by the nearby buildings. A
combination between parametric modelling
tools and solar dynamic simulation software
has been used to optimize the building shapes
in one part of the district (Figure 1). The
analyses demonstrated that the optimized
configuration of the buildings’ volumes could
increase their solar accessibility approximately
from 35% to 50% (Table 1).
ØVRE ROTVOLL: A NET ZERO ENERGY NEIGHBOURHOOD IN TRONDHEIM
ØVRE ROTVOLL: ET NULL-ENERGI BOLIGOMRÅDE I TRONDHEIM
Gabrielle Lobaccaro (NTNU)