Labels and trademarks should give the end-consumer a clear feedback on the quality and performance of the labelled product. Currently there are three labels available for solar products or solar assisted heating systems in Europe, so there is an increasing need to explain the differences to market players as well as customers. The chart above shows the two voluntary collector labels Solergy (left) and Solar Keymark (centre top) as well as the EU Energy Efficiency label (right) which is obligatory for water, space and combi heaters under the Energy Labelling (ELD) and the Ecodesign (EDD) Directives since September 2015.
The first label to be introduced on the market was Solar Keymark. It was developed by the European industry association Solar Heat Europe/ESTIF in co-operation with the European Committee for Standardisation (CEN) in the year 2003. It is a voluntary quality assurance label for collectors and solar thermal systems vouching for compliance with relevant European standards. The Solar Keymark is used in Europe and increasingly recognised worldwide. 463 companies from 41 countries received certificates for their products, totalling 1,394 for collectors and systems up to June 2018.
The label is a simple logo. For the end-customer it does not immediately give any detailed information about the energy performance of the product. However a professional market player can consult the online Solar Keymark database which includes the certification data sheets of all certified products and systems in the market. These data sheets include the annual collector unit output for three different solar radiation sites in Europe (Stockholm, Davos, Würzburg and Athens) and three different collector temperatures (25, 50 and 75 °C). In the latest version of the data sheet the specific output per m² gross area is given as well.