Green Tech Magazine December 2017 en

GREEN TECH MAGAZINE 5
INNOVATIVE. The
Science Tower has
been designed as a
‘Living Lab’. It links
research, development
and industry.
Credits: Harry Schiffer
houses the Green Tech Cluster and other
companies dealing in topics pertaining to a
green future.
100 % renewable energy
From a technological view the Science Tower
is a project used to demonstrate urban technology
aimed at ‘zero emissions’, says Smart
City Graz Project Manager Kai-Uwe Hoffer.
The project’s objective is to supply the city of
Graz with power from the region produced
from renewable sources by 2050. The Science
Tower is part of a local power and energy
network which also includes the large
solar power system running at the premises
of SFL technologies in Stallhofen (SFL energrid).
Using the heat storage system beneath
the building and heat pumps, the tower’s entire
energy demand can be covered with solar
power, says Mario Müller from SFL technologies.
First large-scale use of Grätzel cells
Power is mostly generated through the energy
glass which converts (sun) light into electrical
energy. Contrary to traditional photovoltaic
cells, the energy glass of this Grätzel cell
is dye-sensitised. Its creator, Swiss researcher
Michael Grätzel, invented the principle in the
early 1990s. Similar to photosynthesis, his cells
convert sunlight into energy using a dye. The
glass consists of two coated adjacent panes
of glass with the gap in between filled with a
coloured electrolyte. Thus, it can receive light
“Without a doubt, the Science Tower
will become a magnet –
and not just for Europe but
for the entire world.“
Prof. Michael Grätzel,
Swiss researcher and winner of the
Global Energy Prize 2017
from both sides. Never before have Grätzel
cells been used at such a large scale as on the
Science Tower. The raw material is produced
in Switzerland, refined in St. Marein in Styria,
while the components are prepared for installation
at Stallhofen. Researchers are already
working on the next generation of Grätzel
cells. These are expected to achieve a degree
of efficiency of more than 20 %.
The new sun-powered clock tower
In the summer, the heat produced by the façade
technology is routed into the ground
via the geothermal system using twelve geothermal
probes with a depth of 200 metres
and a length of 2.4 kilometres each. Come
winter, the heat is retrieved from the ground
and increased to heating temperature by the
heat pumps. Another special feature of the
Science Tower is the use of special thin glass
in a large format suitable for buildings and its
moving sun protection system in the façade
which orbits the tower once every 24 hours.
It supplies optimal power yield, provides
shade for the office space and – just like a
sun dial – shows the time, too. “That probably
makes the Science Tower the clock tower
of the right hand bank of the Mur River and
of the digital age,” Mario Müller states with
a smirk.
Building management 4.0
Talking about digital: Thanks to building information
modelling (BIM) – a sort of 4.0 in
building management – the tower’s building
technology is controlled digitally. Using this
technology, a twin of the Science Tower is
created that can be used to simulate many
things: Incidence of light, assembly processes,
facility management and of course costs.
BIM is an enormous help, because changes
in such a large building usually have other effects
and the error redundancy is great. It
is therefore important to work digitally on
the correction of error chains. For ultimately,
several buildings at Smart City are to act as
generators in the future, mini power plants
that will form a large power plant when combined.
www.smartcitygraz.at
info.science-tower.at