The Simplified Method (TSM)

The EU regulations on Ecodesign and Labelling 811-814 apply to space heaters, water heaters and solar devices. They have been under revision since 2017. The revision should make it easier to calculate the efficiency of solar thermal systems and determine it more correctly. In addition, the improved overall efficiency in connection with the primary energy-consuming heat generators should be made more visible to the consumer. A group of experts under the leadership of the European solar thermal association Solar Heat Europe (SHE/ESTIF) developed a comprehensively valid and simple method for assessing solar thermal systems in accordance with EU regulations. The Gross Thermal Yield (GTY) known from the Solar Keymark certification is used as the sole and standardized solar assessment basis to calculate the new assessment parameter "Solar Device Efficiency". In the system calculation, it is equal to the efficiency of a primary energy consuming heat generator, be it a boiler, a heat pump or an electric heating element, and, simply multiplied by the efficiency of the respective heat generator, gives the resulting efficiency of a solar hybrid or solar assisted package. With the new calculation method, it will be possible to achieve the highest class A for water heating and an improvement of up to 2 classes in combination with a heat generator for space heating with normally dimensioned solar systems within the planned reintroduction of the original label classes A-F. This paper reflects the current status of the drafts [1] and [2] of the regulations. The designations, symbols and indices used below are provisional. They are based on the correction proposals of Solar Heat Europe, as the current draft of the EU Commission is still inconsistent and partly incorrect with regard to the nomenclature.