Some traffic and parking areas in urban regions are only occupied for a very limited amount
of time. In particular, this is the case for parking areas of large, suburban cinema centres
which are mostly used only in the evening. Also parking areas of large suburban shopping
centres are largely occupied only in the late afternoon and on Saturdays. The rest of the
week these areas are unused and possess neither productive nor decorative function.
At the same time, a major problem for large-scale implementation of renewable energy, in
particular solar energy and bioenergy, is the massive land use which results from the low
energy density of solar radiation. As it has been remarked repeatedly and correctly, intensive
use of renewable energy can demand areas which are either of high ecological value or
would be needed for other purposes (in particular the production of food and animal fodder).
Therefor it is desirable to employ sparsely used ground-sealed areas, which are already lost
for ecology and for food production, for additional production of energy.
While there are approaches for the use of traffic areas for photovoltaic purposes, the
potential for production of biomass, for example by cultivation of microalgae, has not been
analysed so far. This type of use would offer the advantage that besides the possibility for
energetic use, the harvested algae could also be used as raw material for bio-refineries or for
fertilizer production, allowing for cascade use.
Since this approach is quite new, a main goal is to estimate the potential for this type of
energy and raw material production, based on data on land use, weather data and known
characteristics of microalgae. Another goal is to gain an overview over different possibilities
for implementation and the specific challenges (e.g. mechanical stability, optical properties,
safety aspects).
In particular we will devise a concept for the use of photobioreactors, which are directly
integrated into the traffic areas. If possible, we will collect proposals for possible solutions to
foreseeable problems, e.g. photo-inhibition and protection against freezing.
For this type of analysis, literature research, scientific calculation and simulations with (rather
simple) computer models will be employed. From results of calculations and simulation we
will derive a catalogue of criteria to describe which approaches seem feasible, which
minimum requirements the construction materials have to fulfil and which are the limiting
economic factors for a profitable implementation.
Based on these results, the approach will be compared with alternative concepts (like
photovoltaic use and light harvesting) and strategy recommendations will be devised. All in
all, this project will yield new approaches and insights for biomass production on spaces
already used for traffic and will therefore offer new perspectives for management of energy
and material in the urban environment.