Energy optimised design rules and integral planning approach for building-integrated photovoltaics in urban areas (VITALITY)

Initial Situation/Motivation

Austria has committed itself to the international climate targets and to an active climate protection and energy policy. The central goal of the Austrian Federal Government's climate policy is to reduce greenhouse gas emissions by 36 per cent by 2030 compared to 2005. The #mission2030 Climate and Energy Strategy formulates the path to a climate-friendly society. One goal is to generate electricity by 2030 to an extent that the national total electricity consumption is 100 per cent (national balance) covered by renewable energy sources.

Photovoltaics will play an important role in the future electrical energy system and a massive rollout of photovoltaics is imminent. To prevent the further sealing of valuable land areas by the construction of photovoltaic power plants, the use of the sufficiently available building surfaces is expedient.

A solar transformation of architecture is pending. Falling prices for solar modules and solar electricity mean major challenges for the construction industry. Building planning in urban areas requires an effective and integral planning approach for implementing building-integrated photovoltaics (BIPV) successfully. The lack of sufficient tools and proven and easy to apply design rules are barriers, especially for non-PV specialists.

Objectives

The VITALITY project aims to provide supporting tools, design rules and robust information in the early decision and design phase of building projects. By providing the right information at the right time, building-integrated photovoltaics (BIPV) is part of the discussion in the concept phase and the implementation is strongly prepared and supported.

Method

The VITALITY project team has chosen two different approaches to methodically demonstrate the BIPV potential for a construction project in the early design phase.

First approach

The VITALITY project team chose to develop an application to respond to individual building geometries and uses. Simplified calculation components were implemented in the existing tool environment Rhinoceros and Grasshopper^®. The VITALITY tool visualizes technical BIPV solutions and shows the module placement with regard of energy and economy indicators – like self-consumed solar electricity and simple payback time.

Second approach

For representative building typologies in an urban context, ranges of energy and economic key figures were determined. Furthermore, a broad database was created based on the calculation results of parameter studies by means of simulation to extract design rules for certain applications.

VITALITY products are

• Developed simulation environment for 3D visualization of BIPV allocation according to energy and economic aspects.
• Developed optimization algorithm for the economic placement of PV modules on any building surface.
• Developed simplified approach for the generation of electricity profiles for different energetic building concepts in office and residential buildings.
• Extracted simplified design rules based on the results of numerous modelling and simulation studies.
• Defined ranges (low, medium and high occupancy) for selected building typologies to identify valid scopes for different BIPV design variants in terms of self-consumption ratio and self-sufficiency.
• Investigated and documented use cases to check the functionality and performance of the developed methods and algorithms.

Projektleitung

• Tim Selke, Marcus Rennhofer, Thomas Schlager
  AIT Austrian Institute of Technology GmbH

Projektpartner

• Sebastian Sautter, Martin Kaftan
  Technische Universität Graz / Institut für Gebäude und Energie
• Anita Preisler
  teamgmi Ingenieurbüro GmbH
• Gernot Becker, Oleg Stelzhammer
  ATB-Becker e.U.
• Marco Lovati
  Accademia Europea di Bolzano
• Jouri Kanters
  Lund University/ Faculty of Engineering / Department of Architecture and Built Environment