Bo Carlsson, SP Swedish National Testing and Research Institute, Sweden Stefan Brunold, Institut fur Solartechnik SPF Hochschule Rapperswil, Switzerland Andreas Gombert, Fraunhofer Institut fur Solare Energiesysteme, Germany Markus Heck, Fraunhofer Institut fur Solare Energiesysteme, Germany

To achieve successful commercialisation of new advanced windows and solar fa­cade components for buildings, the durability of these need to be demonstrated prior to installation by use of reliable and well-accepted test methods.

In Task 27 of the International Energy Agency Solar Heating and Cooling Pro­gramme, a general methodology for durability test procedures and service lifetime prediction (SLP) methods therefore has been developed that should be adaptable to the wide variety of advanced optical materials and components used in energy efficient solar thermal and buildings applications. The general durability assess­ment methodology is now adopted to some static solar materials to allow prediction of service lifetime.

Introduction

The IEA Solar Heating and Cooling Programme, Task 27 on the Performance of Solar Fa­cade Components started at the beginning of year 2000 with the objectives of developing and applying appropriate methods for assessment of durability, reliability and environ­mental impact of advanced components for solar building facades [1].

For the work on durability there are two main objectives. The first is to develop a general framework for durability test procedures and service lifetime prediction (SLP) methods that are applicable to a wide variety of advanced optical materials and components used in energy efficient solar thermal and buildings applications. The second is to apply the ap­propriate durability test tools to specific materials/components to allow prediction of service lifetime and to generate proposals for international standards.

As the result of this work, a general methodology has been developed [2], which is now adopted to some static solar materials. The work is performed in three case studies on anti-reflective glazing materials, reflectors and solar facade absorbers. Anti-reflective ma­terials that are studied include sol-gel coated and etched AR glasses. Reflectors that are studied include aluminium alloy based mirrors; some protected by clear coats, and glass mirror reflectors. Solar Fagade Absorbers that are studied include coloured sputtered se­lective solar absorber coatings, absorber coatings made with sol-gel technology and thick­ness insensitive spectrally selective paints.