H. Drtick*, H. Mtiller-Steinhagen

University of Stuttgart, Institute for Thermodynamics and Thermal Engineering (ITW) Pfaffenwaldring 6, 70550 Stuttgart, Germany Tel.: +49 711 / 685-63553, Fax: +49 711 / 685-63503 Corresponding Author, email: drueck@itw. uni-stuttgart. de

Abstract

In the years 2000 and 2001 the first edition of the European standards for solar thermal systems and components was issued and started to replace all related national standards /1/. The three standard series are related to solar collectors as well as to factory made and custom built solar thermal systems. During the past four years the standards were revised and updated.

Based on the European standards, Solar Keymark certification was established in 2003. The Solar Keymark is the official CEN certification scheme for thermal solar collectors and factory made thermal solar systems /2/. Although the Solar Keymark is still relatively young, more than two thirds of all solar thermal collectors sold in Europe are already qualified with a Solar Keymark label. The specific Solar Keymark scheme rules forming the basis for Solar Keymark certification were revised and updated during the past two years. This was done to adopt the Solar Keymark certification process to present developments and to make Solar Keymark certification of factory made systems less expensive by introducing a so-called “flexible Solar Keymark certification” for system families or product lines respectively.

This paper describes the important changes and highlights resulting from the revision of the European solar standards. With regard to Solar Keymark certification, notable changes in the specific Solar Keymark scheme rules will be pointed out and the approach for flexible Solar Keymark certification will be discussed.

Keywords: European standards, Solar Keymark, testing, certification

1. Introduction

The solar thermal market is growing very dynamically. In order to ensure a certain amount of transparency and quality as a basis for a sustainable market development the existence of uniform standardised test procedures and product certification schemes are very important aspects.

With regard to the elaboration of European standards for solar thermal products the work started almost 15 years ago with the establishment of the European Standardisation Committee CEN TC 312 (CEN: Comite Europeen de Normalisation; TC: Technical Committee) in the year 1994. This activity was based on a proposal of the European manufacturer association ESIF (European Solar Industry Federation) which is today named ESTIF (European Solar Thermal Industry Federation). In the standardisation committee CEN TC 312 experts from industry as well as from research and testing institutions work, divided into several working groups, on aspect related to standardisation.

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This first set of European standards for solar collectors, ‘factory made systems’ and ‘custom built systems’ was issued in 2000 and 2001 /1/. During the last two yeas these standard were revised and updated. The most important aspects resulting from this activity are described in chapter 3 to 5.

The Solar Keymark is the official CEN certification scheme for thermal solar collectors and factory made thermal solar systems. It requires that the products fulfil the requirements of the European Standard series EN 12975 and EN 12976 and that this is confirmed by an accredited testing laboratory. Furthermore, additional requirements such as yearly inspection of the production line and physical inspection of the product itself every second year, have to be fulfilled.

Although the Solar Keymark is relatively young, as it was introduced to the market in 2003, up to now (summer 2008) approximately two thirds of all solar thermal collectors sold in Europe are already qualified with a Solar Keymark certificate. An overview on Solar Keymark certification is given in chapter 6.