Foto: Frontansicht des Wohnhauses in der Makartstraße, Linz

URSOLAR - Optimization of SOLAR energy usage in URban energy systems

URSOLAR provides decision makers with a roadmap for the integrated use of solar energy in urban environments. The roadmap shows, how photovoltaics- and solar-thermal installations can be used in an ecological, economical and socially optimal way whilst considering legal requirements as well as infrastructural conditions in typical city quartiers and stakeholder interests.

Short Description


Starting point / motivation

Solar energy (heat and electricity) still plays a minor role in the urban energy system. Due to the fact that solar technologies include numerous benefits (e.g. zero emissions of noise, greenhouse gases and air pollutants or the general availability of the energy source), a more important role of solar energy is desirable in the city of the future. The local use of solar energy depends on different conditions, like availability of energy infrastructure, limited space as well as competition for space between solar technologies. Due to the fact that solar energy outputs are volatile during the day as well as during the year, the supply of energy does not equal its demand frequently. For the effective use of solar-energy it would be highly relevant to identify systemic solutions which are adjusted to specific city quarters and their infrastructural conditions as well as to avoid transformation losses and to relieve the load on the grid. Relevant systemic solutions could be the inter-building usage of produced energy, micro grids, energy storage options, power-to-heat technologies as well as the integration into the existing net in times of higher demand. To use these systemic solutions suc-cessfully in urban city quarters, target group specific business models need to be developed, con-sidering a wide range of stakeholder interests.

Interests and competencies of stakeholders relevant for the successful implementation of business models in urban areas differ from those in suburban areas. Besides general (social) criteria which are related to the implementation (e.g. income, acceptance etc.), especially property-law and ener-gy-law related problems present themselves as hindrances. Therefore, the decision to initialize a solar energy project as well as the selection of an adequate business model depend on numerous aspects.

Contents and goals

It is therefore a complex task to find combinations of systemic solutions and business models ad-justed to specific urban city quarters. The goal of URSOLAR is to develop an integrated roadmap for the urban solar-energy use that depicts ways of how solar-technologies can be used optimally in three urban environments, given the infrastructural and legal conditions as well as stakeholder in-terests.


In two approaches technical systemic-solutions as well as organizational implementation models will be developed. Based on primary and secondary data, the technical and social frameworks in the chosen urban areas will be analysed. These urban areas are representative for urban areas in Austrian cities. The approach enables the identification of the most important factors for successful and unsuccessful implementation of solar-energy-systems. A constant stakeholder dialog accom-panies the project and enables a transdisciplinary sustainability assessment of the developed roadmap.


The added value of URSOLAR lies in an inter- and transdisciplinary roadmap that depicts ways for the economic, ecological as well as social sustainable usage of solar-energy in urban environ-ments. These ways are fitted to the individual needs of the analysed urban environments and are integrated into the available systems. The project results also serve the strategic expansion of solar energy usage in urban environments as well as the integration in the urban energy-grid.

Prospects / Suggestions for future research

The importance of house-management organizations for the successful implementation of solar energy systems needs to be more profoundly addressed in the future. Scientific literature rates the influence of perceived fairness during the implementation process as high as a combination of all sociodemographic factors together. During the URSOLAR project it has become clear that house-management organizations are playing a crucial mediation role between stakeholder interests. These organizations not only serve as the formal implementation routine for solar-energy-projects but are increasingly often responsible for the success or failure of the project itself, if they manage to mediate between different interests. To foster the implementation of solar-energy-projects in ur-ban environments, future research projects should focus on this factor and analyze ways of how communication- and consent-procedures can be effectively developed among stakeholders.

The approach "energy should be generated where it is demanded and vice versa" leads to tech-nical energy system solutions, which must be adapted individually to the respective energy techno-logical framework conditions. Combined solutions of PV and solar thermal energy collectors can represent quite economically interesting solutions in the future, whereby the design of the solar thermal system should be based essentially on water heating. The importance of self-utilization of energy in micro grids ("prosumers") is particularly interesting from a technical point of view as soon as a combination of different types of users (residential construction / commercial / industrial) with different utilization profiles are available within the urban city quarters. In regard to solar heating, (low temperature) micro grids in urban city quarters are preferred to large scale district heating sys-tems since the efficiency of the solar thermal system decreases when feeding into a (high tempera-ture) district heating network. For the use of PV electricity, the adaptation of the legal framework would be beneficial, especially for multi-family houses (several metering points), to provide PV elec-tricity for the apartments in addition to the common area electricity (possibly in combination with smart meters).

From a legal point of view, the planned amendment of the Electricity Act (insertion of a new § 16a on joint in-house generation facilities) will considerably facilitate the construction of urban solar en-ergy projects. Need for legal reform will persist in tenancy and real estate law. Amendments in these areas (e.g. by allowing the shifting of construction and operating costs towards tenants and co-owners) could further boost the interest in the construction of solar energy projects on multi-family buildings. 

Project Partners

Project management

University of Graz, Institute of Systems Sciences, Innovation and Sustainability Research

Project or cooperation partners

  • Grazer Energieagentur Ges.m.b.H.
  • University of Graz, Institut für Österreichisches, Europäisches und Vergleichendes Öffentliches Recht, Politikwissenschaft und Verwaltungslehre

Contact Address

Karl-Franzens-University Graz
Institute of Systems Sciences, Innovation and Sustainability Research
Merangasse 18
A-8010 Graz

Alfred Posch
Tel.: +43 (0) 316 380 - 3234

Christiane Reischl
Tel.: +43 (0) 316 380 - 1520

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