ECONOMIC VIEW OF THE PROJECT

Building integrated Photovoltaic systems should not only be valued regarding their investment costs. The low operating costs of highly energy efficient buildings with a significant share of electricity produced by Photovoltaics have a long term value. In the ENERGYbase office, the occupants can enjoy very low operating costs. The specific electricity consumption per square meter useful floor area from the grid is only 14.4 - 18.1 kWhel. This means the specific energy costs for the building operation including ventilation, pumps, heating and cooling are only 2.88 – 3.62 € per useful area and year. This is extremely low.

INTEGRATION OF PHOTOVOLTAICS INTO THE DESIGN

The integration of solar and other renewable energy production and energy conscious design go hand in hand. In this process integration of PV in the building design and structure must not only mean lowering the efficiency of PV due to ‘design concessions’ such as color printing or other colors minimizing the efficiency. The structural integration into the design plays a significant role as well as does the functional integration.

CONTROLLING THE DETAIL IN PV-FACADES

The detailing plays a significant role in the performance of photovoltaic façades. While the free ventilation and the reflections of the glazing play a very positive role the effect of small projecting parts causing shade can’t be overestimated. Just minimal overlaps can cause long shades in the vertical as to be seen with the solar module overhang in this project. The geometry must be ambitiously controlled in every detail in PV-façades to avoid any shading.

COMMMUNICATIONS AND SOLAR ARCHITECTURE COMMITMENT

The ‘Future Base’, built ca. 10 years later by the same owner and the same occupant was built as a highly efficient building. But no special solar design was applied, only a minimum of roof top PV. However the general energy standard and the main components of the energy system were copied from the ENERGYbase to this building as well as to another building in Aspern. Obviously the engagement of a ‘solar architect’ is still a must have for an advanced ‘solar design’.

PUBLIC FOUNDING FOR EXTENDED BUILDING DESIGN RESEARCH VERY VALUABLE

To be able to do such extensive simulations and differentiated planning process as well today a public research funding will be necessary. More research programs as such should be carried out.

OPEN SPACES ARE OPTIMAL FOR COMMUNICATION ZONES AND COMMON USAGES, BUT NOT FOR INDIVIDUAL WORK PLACES

The open space looks great and is very functional as a community area, but proofed not very favorable in terms of individual work places. While the option for a spatial division into single rooms would have been easy to be planned it was not done. As the ventilation concept is laid out for cross ventilation from south to north it is not easy enough to change this spatial arrangement. However with user’s needs known as today the façade concept could have been easily adapted to the wish for privacy and a silent working environment. Furthermore each user should have access to individually openable windows. So flexibility in use should include the option of individualization regarding office work spaces. This needs to be reflected in HVAC-concepts as well.

TODAY WE COULD REALIZE IT "PLUS ENERGY"

At the time being it was not possible to directly sell the solar electricity from the building and PV-owner to the occupants. Today there are other options recently opened in Austria for ‘community PV-plants’. This means today much more PV could be installed on the building to make it ‘plus energy’ or to supply as well the user’s electricity needs with solar power generated by the owner.