Plus-Energy-Campus - Energy-flexible Positive Energy District with "Living Lab"

Status

abgeschlossen (2022)

Starting point / motivation

The Plus-Energie-Campus research project addressed the central question:

Are the project goals

• Plus-Energie-Campus (new university building and additions as plus-energy buildings)
• Plus-Energy-Quarter at Höchstädtplatz
• Living Lab at the Plus-Energy-Campus considering adapted forms of teaching and a vision for R&D projects

technically feasible and economically justifiable?

To answer these questions, different structural solutions (location, architecture) and energy concepts were developed for the campus, and their ecological and economic impacts were evaluated and compared. The energy concepts for the Plus Energy Campus were also applied to the entire Höchstädtplatz neighborhood. In addition, the installation of deep drillings for geothermal energy use and the joint construction of an anergy network were examined at the neighborhood level.

At the campus level, a mobility concept was developed. This concept was used to check whether the reductions in traffic emissions included in the assessment at the neighborhood level are realistically achievable. An economic evaluation of the measures of the mobility concept was only carried out in very rough outlines and was not included in the total costs.

In order to present the interrelationships more clearly, the starting point, methods and results for the Plus-Energy-Campus, the Living Lab and the Plus-Energy-Quarter have each been summarized in a chapter in this report.

Plus-Energy-Campus

The FH-Technikum Wien is growing and for years there has been a need for additional space for teaching and research. At the time of writing, this is housed in 4 buildings at Höchstädtplatz and in parts of the Energy-Base in the 21st district. These buildings were constructed between 2003 and 2013.

Three structural variants for the expansion of the areas of the FH-Technikum Wien were investigated: two post-densification variants to the existing A-building and an additional building in the area of the existing building complex. The results differ only marginally in terms of energy, ecological and economic considerations.

The energy concept focuses on:

• optimization of the thermal envelope (insulation and windows)
• optimization of heat and cold generation and dissipation (building component activation, heat pumps, underfloor or surface heating)
• increasing the efficiency of ventilation (heat recovery, ...)
• the use of renewable energies (generous use of photovoltaics, wind peak shaving)
• the optimization of the electrotechnical installations

Energy flexibility is foreseen especially in the area of heating/cooling generation and delivery (heat pumps with storage). Electrical storage has not been envisaged. The use of e-vehicle batteries as intermediate electrical storage was investigated, but was not included in the calculation of the impact of the measures due to a lack of practical experience and difficulty in estimating the actual potential.

The results of the simulations show that the plus-energy standard at building level can only be achieved for all structural variants if all measures are implemented.

The economic considerations show that the costs of the measures are offset in the long term by the reduction in energy costs. There are very large differences in the payback periods of the individual measures, which is mainly due to the fact that the existing buildings from the 2000s have a comparatively good thermal envelope, which means that the additional energy savings are lower than for other buildings in need of renovation (e.g. built before the 1980s).

The implementation of the plus-energy standard with the inclusion of ecological building materials and the impact on the life cycle assessment was also investigated:

• Contribution to global warming (indicator: GWP-total).
• Acidification of soil and water (indicator: AP)
• Demand for non-renewable primary energy, total (indicator: PENRT)
• Demand for renewable primary energy (PEE)

The life cycle assessment shows that the life cycle environmental impacts can be greatly reduced with a renovation to plus-energy standard with additional use of building materials that are as environmentally and resource friendly as possible. However, the differences between the building variants are marginal compared to the energy variants.

The economic analysis here shows additional costs of around 20 %.

Plus-Energy-District at the Höchstädtplatz

The quarter comprises eleven building blocks (micro quarters) with a usable floor area of 175,959m2. Two construction blocks are currently in the process of being rezoned/redesignated, and one block is in the construction phase.

The areas are used 70% for residential, 14% for offices, 11% for education and 5% for retail. Buildings were 39% constructed before 1978, 38% constructed by 2009, and 23% constructed 2009-2015.

The evaluation of the Plus-Energy-Standard is based on the definition approaches of the Zukunftsquartier project series (Zukunftsquartier 2.0 and ZQ Austria

The simulation results show that the following conditions are necessary to achieve the Plus-Energy-Standard in the quarter:

• A renovation rate of 2.82 results in renovation of all buildings until 2040 except.
  o Brigittapassage (21% built after 2009, 71% after 1979)
  o residential tower (built in 2006) and
  o FH-Technikum-Zeile (built after 2010) until 2040).
• "out gas" (fictitious conversion to district heating as starting point)
• "PV offensive" (covering all roofs and suitable facades with PV)
• Switch to renewable energy sources for heating/cooling (air-source or ground-source heat pumps)

Here, too, the economic analysis shows that the costs of the conversion will be covered by energy savings in the long term. For the most part, the payback period for the measures is less than 30 years. The use of geothermal energy by means of deep drillings and heat exchange between the buildings by means of an energy network is economically more expensive than the conversion to air heat pumps, but makes an important contribution to energy flexibility and efficiency and is therefore an important prerequisite for achieving the Plusenergiestandard of the neighborhood.

Living Lab

The project results show that the contributions of the various implementation options of the Living Lab, with regard to the specific topic of sustainable building and district structures in the larger context of university activities, to the general objective of the concept as an accumulator of sustainable development can be regarded as positive in most cases.

In the case of innovative measures in the planning and development of climate-fit and thus sustainable urban quarters, there is often still a considerable need to ensure the general acceptance of technologies and processes used. In this context, the university can serve as an interface between the training of future professionals in its different thematic fields of teaching and those people who use the same neighborhood and thus stay in the same neighborhood-defined space. The general objective of applying technological developments in an "open" framework and over longer periods of time in varying, experimental settings can be extended to include a transdisciplinary dimension, especially in the urban setting of a university focusing on technical topics, in which actors from civil society as well as representatives of local companies and regional decision-makers are involved in these processes.

Summary

Achieving the Plus-Energy-Standard is achievable for the campus of the FH-Technikum Wien as well as for the neighborhood at Höchstädtplatz. The establishment of a "Living Lab" in the course of the expansion of the FH-Technikum Wien can contribute to raising awareness and acceptance of the measures. The investments required to achieve Plus Energy status will be offset by energy savings over very different periods of time. While investments in a comprehensive, generous use of photovoltaics and thermal refurbishment of older buildings are compensated by energy savings in the very short term, even without subsidies, the investment in geothermal heat pumps and an energy network only pays for itself with sufficient subsidies from the public sector. The thermal refurbishment of younger buildings only pays off in the long term, but is essential for achieving the Plusenergiestandard in relation to the building.

Project management

Fachhochschule Technikum Wien

Project or cooperation partners

• IBO – Österreichisches Institut für Bauen und Ökologie GmbH
• POS architekten ZT GmbH
• Teamgmi Ingenieurbüro GmbH
• SOMMERAUER Projektmanagement GmbH

Kurt Leonhartsberger
Hochstädtplatz 6
1200 Wien
Tel.: +43 (664) 619 25 86
E-mail: leonhart@technikum-wien.at
Web: www.technikum-wien.at