Model for a Sustainable Energy Concept for Austria

In many countries such as Austria the energy demand is mainly covered by fossil fuels. Over the last decades the negative impact of fossil fuels on the climate became apparent and has been largely investigated. Furthermore the usage of fossil fuels can not be durable and stable over a long time period. This brings up the need for modelling a possible future energy system using solely renewable energy sources.

The goal of the project ZEFÖ is to compare and possibly match the energy demand of Austria with the long-term potentials of Austria’s renewable energies. Different possible full coverage scenarios of the energy demand should be visualized and analyzed, while taking into account the trade-off between using biomass for food, for animal feed, for material usage and for providing energy carriers.

To reach this goal we developed a static model of different energy demand scenarios versus all the different energy sources available per year. The model contains many parameters for an easy change in the settings on the supply side as well as on the demand side for studying the influence on the balance. We use a top-down modelling approach for the energy balance using statistical data and we employ bottom-up modelling for parts of the system where this seemed necessary, due to high efficiency or trade-off potentials.

Varying parameters also allows to examine the effects of enforcing or reducing various energy supply and energy conversion technologies. The profound modelling of the areas of space heating (including hot water) and mobility on the demand side makes it possible to consider changes in the structure of buildings, the population number and the mobility behaviour, as well as the transportation structures. The forestry and the agriculture areas on the supply side are also modelled bottom-up to be able to simulate changes of the alimentation behaviour, the woodworking industries and the agricultural system. The total effects of such changes on the energy system and its balance can then be looked at and analyzed.

Technically the model is realized in the object-oriented programming tool GaBi by a functional combination of processes. The most processes describe a conversion of energy/material into a different form, e.g. a wood stove converting 1 kg dry wood into 20 MJ heat. But also the correlation between area and energy or energy and energy services is realized through processes. Connecting the processes via flows and sub-modelling processes hierarchically allows for modelling even the most complex energy systems.

Our conclusion is that - against common opinion - it is possible to provide full coverage of Austria’s energy demand by just using renewable energy sources, even with the still existing technologies. However there have to be significant changes in the structure of buildings introducing high construction standards to reduce the loss of heat drastically and mobility technologies have to change towards electrical drives having much higher conversion efficiencies.