The Joint Research Centre (JRC), the science and knowledge service of the European Commission, has published message with the title "Harmonized rules for the calculation of the carbon footprint of photovoltaic modules in the context of the EU Ecodesign Directive". This document aims to provide scientific support for EU policy-making and illustrates the proposal for harmonised rules for accounting for the carbon footprint of photovoltaic (PV) panels. These rules have been designed to be applicable in a regulatory context, specifically for products falling within the scope of theEU Ecodesign Directive (2009/125/EC)The report supports the development of a preparatory study to assess the feasibility of ecodesign and/or energy labelling requirements for the product group of PV panels, inverters and systems.

The method presented in this report is based on the PEFCR (Product Environmental Footprint Category Rules) for PV modules and defines harmonised calculation rules for carbon footprint assessment in a regulatory context. The resulting method is the result of a consensus-building process based on different stakeholder views received at different stages. Two main stakeholder consultations were held, the first on 27 June 2022 and the second on 30 March 2023, during which a total of 80 written comments were received.

When calculating the carbon footprint of PV panels according to these harmonised rules, a functional unit is defined as one kWh (kilowatt hour) of the total direct current electricity generated during the lifetime of a photovoltaic module. The reference flow is the amount of product (in m²) needed to fulfil this function. The system boundary includes the specific life cycle stages and processes of PV modules, including raw material acquisition, pre-processing and module manufacturing, as well as distribution.

The rules set requirements for the type of data to be used. Manufacturers must use company-specific (primary) data for certain mandatory processes, such as the production of photovoltaic panels and distribution to a regional warehouse. For other processes that are not mandatory, the Data Needs Matrix (DNM)If the company does not have access to specific information, the following will be used: default secondary datasets and default activity dataData quality rating (DQR) for default secondary datasets is also an important aspect.

The modelling includes various aspects of the life cycle, such as the transportation of raw materials and intermediate products, for which default distances and scenarios are provided if company-specific data are not available. Recycled content and end-of-life recycling of materials are also modelled using the Circular Footprint Formula (CFF). The modelling of electricity consumption is another key element, with priority given to on-site electricity generation, followed by other types of electricity mixes, including residual consumption mix.

The report presents carbon footprint results for mono-crystalline and multi-crystalline silicon PV panels in different scenarios. For mono-crystalline silicon the carbon footprint results ranged from worst case scenario 4.40 E-02 kgCO2 eq. per kWh to best case scenario 1.08 E-02 kgCO2 eq. per kWh, which represents a fourfold difference. For multi-crystalline silicon the results ranged from worst case scenario 5.01E-02 kgCO2 eq. per kWh to best case scenario 1.78E-02 kgCO2 eq. per kWh, representing a nearly three-fold difference. Analysis of mono-Si panels showed that materials significantly affect the carbon footprint, with an aluminum ingot contributing 16.92 % in one scenario. The lifetime of the product also plays a significant role in the carbon footprint per kilowatt-hour. For example, reducing the lifespan of a 30-year panel to 20 years can lead to a 1.5-fold increase in carbon footprint.

These harmonised rules provide a structured approach to assessing the environmental impact of PV modules in the EU, taking into account material inputs, production processes and logistics throughout the product life cycle. Supporting the development of a dedicated online tool to calculate the carbon footprint of PV panels will further facilitate the implementation of these rules. Spring