Vienna is becoming a city of solar power

In order to achieve Austria’s climate target of only consuming electricity from renewable energy sources by 2030, the use of photovoltaics needs to be expanded to as much as 11 TWh. We will invest EUR 480 million in adding 600 MW of photovoltaics between now and 2030. The small amendment to the Green Electricity Act means that we can now push ahead with the installation of PV systems on the roofs of apartment buildings, turning Vienna into a city of solar power and cutting CO2 emissions by almost 200,000 tonnes every year.

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Background information

The small amendment to the Green Electricity Act, which came into force in 2017, has paved the way for the construction of collective generation facilities, with tenants or owners in apartment blocks and office buildings being able to come together to share a PV system. Installing PV systems on the roofs of apartment buildings is hugely important, especially in metropolitan areas with dense architecture such as Vienna, making it possible to safeguard the supply of renewable electricity to the city and thereby helping maintain the high quality of life in Vienna.

  • Around 30 percent of annual electricity needs can be met with a rooftop PV system, provided that the electricity generated is consumed by the producer and not fed into the grid, as this makes it possible to cut CO2 emissions, energy costs, network charges and taxes that would be incurred if electricity were drawn from the grid.

  • Passive energy users become active prosumers who play an important role in the energy system transformation.

Theoretically speaking, any surface that is exposed to direct sunlight can be used for photovoltaics. However, in practice, only surfaces that can be developed in an economically viable way are used to produce solar power. Moreover, technical parameters such as safety clearances and skylights must be taken into account. What this means is that around 10 percent of rooftop space available on Vienna’s some 68,000 apartment buildings is suitable for having collective generation facilities installed.

Wien Energie built its first collective PV system on Lavaterstraße in Vienna’s Donaustadt district. With a surface area of 400 m2, the PV system can be used to supply 48 households with solar power from their own roof. Any surplus electricity is fed into the grid.

Michael Strebl

“The sun is turning roofs into power plants – right in the heart of the city. The opportunity to share solar power among the individual residents of a building opens the door to completely new business models, enabling us to make huge strides forward in our work to expand the use of photovoltaics in Vienna.”

Michael Strebl, General Manager of Wien Energie

Our demands

A suitable legal framework is needed to enable the full expansion of PV on the roofs of Vienna in order for the city’s population to be able to actively participate in the energy system transformation.

To this end, Austria’s climate and energy strategy envisages the launch of a programme to install 100,000 rooftop photovoltaic and small-scale storage systems. An investment subsidy was also announced and the decision was taken to abolish the tax on self-generated electricity. What will be of key importance, however, is the removal of obstacles in residential legislation to investment in order to make it easier to build collective PV systems, as the current requirements to obtain consent often stand in the way of a system being installed.

  • The current requirement to obtain the approval of every apartment owner serves to hinder the installation of collective PV systems. Including PV systems on the roofs of apartment buildings on the list of measures of ordinary administration (Section 28 WEG) would make it possible for a minority of apartment owners to install a corresponding system for their own benefit and at their own expense.

  • Moreover, the fact that an apartment owner is absent from the owners’ meeting would not be construed as them rejecting the installation of a PV system on the roof, as would have been the case in the past, but rather as agreeing to it. As experience shows that PV projects in apartment buildings often fail precisely because of this reason, this would make it much easier to implement such projects in the future.

Tenants currently do have the right to install PV systems on the roofs of apartment buildings. As such, the Tenancy Act (Mietrechtsgesetz, MRG) needs to be amended to have PV systems included on the list of useful improvements to buildings (Section 4 MRG), giving tenants the legal right to install a rooftop PV system at their own expense. This would make it considerably easier to install a PV system, provided it is economically and technically feasible.

Further information

Your contact person

Lisa Henhofer
Lisa Henhofer

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