Optimization of energy supply

Status

finished

Summary

Purpose of the work

The purpose of the work was to analyze the possibilities of the reduction of the energy demand of residential buildings by using advanced telecommunication technologies and to assess the possibilities with respect to practical application, personal data protection and costs.

Motivation

The motivation of reduction of the energy demand of the "Buildings of Tomorrow" are needs of climate protection by reduction of the use of fossile energy sources and the goal to improve economy of residential heating.

Contents and methodology

The project has been carried out in 4 main tasks:

1. Analysis of the energy-relevant components and systems considering the use of information technologies and bus systems

   The purpose of this task was to investigate energy-relevant components of the "Building of Tomorrow" in view of interfaces for information technologies and to investigate the possibilities of the use of information technologies for an intelligent energy management of the "Building of Tomorrow".

2. Internal energy management of the "Building of Tomorrow"

   The purpose of this task was the search for an optimized control strategy for energy-relevant devices and building components using extended innovative information technologies to achieve a comprehensive energy optimization of the "Building of Tomorrow".

3. External energy management of the "Building of Tomorrow"

   The purpose of this task was to investigate the possibilities and effects of controlling the energy-relevant devices and building components of the "Building of Tomorrow" using innovative information technologies from a distant location.

4. General concept for minimization of energy demand of the "Building of Tomorrow"

   In this task a general concept for minimization of the energy demand of the "Building of Tomorrow" has been developed considering the results of the previous tasks.

Results

The component of highest relevance in view of the reduction of the energy demand using information technologies is the heating system. The most effective measure in this field is the lowering of the room temperature set point during the absence of the occupants.

The effect of lowering the temperature in general depends on the following parameters:

• Climatic conditions
• Construction of the building in terms of heat transfer coefficient heat storage capacity of the walls
• Duration of temperature lowering

Model calculations for model houses, carried out by the Institute of Thermal Engineering, TU-Graz show under typical Austrian climatic condition the following results:

• Lowering the temperature is already effective during a few hours. By lowering the temperature from 21 °C down to 15 °C during the night for example, a reduction of some 10 % of the energy demand of a wooden building can be achieved in the annual average. In concrete buildings, the reduction of the energy demand is some 7 %. In a weekend cottage the possible reduction is some 20 %.
• Also during non periodic absence the energy demand of the building can be reduced significantly. Lowering the temperature from 21 down to 5 °C during "1-week holydays" for example leads to a reduction of the energy demand in case of a wooden building of some 60 %, and in case of a concrete building of some 23 %. During "3-week holydays", some 75 % of the energy demand of a wooden building, and some 40 % of the energy demand of a concrete building can be saved.

This is possible by state of the art information technology as well as innovative information technologies entering the market. Automatically control from a distant location with the goal of minimizing the energy demand of the building is possible today, but such methods are not really applied to heating control up to now. Cost of such innovative information technologies are low in relation to the benefit of the energy cost reduction achieved. Building planners and users therefore should consider the possibilities of energetic optimization of the "Building of Tomorrow" by using innovative information technologies.

Contact

Reinhard Padinger
Joanneum Research, Institute of Energy Research
Elisabethstraße 5
A-8010 Graz
Tel.: +43 0316 876 1333
Fax.: +43 0316 876 1320
E-Mail: reinhard.padinger@joanneum.at