At Ines, Nouha Gazbour, researcher on the sustainability of photovoltaics, and Delphine Cherpin, deputy director of the solar technologies department at CEA-Ines, are working on the eco-design of solar panels to combine ecology and economy.
Researcher at Ines
Actu-Environnement: What is the environmental impact of photovoltaic panels currently on the market?
Nouha Gazbour : Their carbon footprint has dropped significantly since 2014-2015. In reference sunny climatic conditions, it is, on average, between 20 and 30 grams of CO equivalent2 per kilowatt-hour (gCO2e/kWh). The module manufacturing phase accounts for most of the greenhouse gas emissions attributed to photovoltaic panels. This is mainly due to the nature of the energy mix of the countries where the manufacturing units are established, in particular China, which is mainly fueled by coal.
An exponential technological evolution has made it possible, in recent years, to increase performance, but also to reduce manufacturing costs. Adding to this the strengthening of regulations, this development has also led to an improvement in the carbon footprint of the panels.
Delphine Cherpin : Photovoltaics is far from representing an ecological disaster. It is already positioned in European standards in terms of recyclability. The glass and the aluminum frame are already recycled. But, at the National Institute of Solar Energy (Ines), we think we can go further: optimize the use of certain resources, such as silver, copper or silicon, or even replace them to make the technology photovoltaic as virtuous as possible.
AE: How can this environmental assessment be improved and how can eco-design play a role?
NG : Relocating their manufacturing to Europe, to countries like France or Norway, with much cleaner mixes, is an option for reducing the environmental impact. Nevertheless, this would most likely result in increased costs. The other option, on which we are working within the Institute for Ecological Transition (ITE) Ines.2S (co-financed by the State as part of the France 2030 plan), is to eco-design all or part of a panel solar.
In this way, it will also be possible for us to better anticipate its end of life: optimizing the environmental impact of manufacturing can lead us to achieve a higher degree of recyclability of materials.
AE: What materials do you take into account in your work and how can you determine their environmental benefits?
DC : We cannot communicate on the “recipes” strictly speaking, but we favor materials, which facilitate the dismantling of the “sandwich” of the photovoltaic panel and the recycling of materials such as composites based on natural fibers, such as fiber linen, combined with bio-sourced thermoplastic resins. We use them to replace the glass used on the front side and the glass (or the fluorinated polymer sheet) on the back side.
We develop samples, in the form of a four-cell module the size of an A4 sheet, whose performance and durability we measure within climatic chambers, under various conditions of sunshine for several weeks. This allows us to know their profitability and to predict their aging.
A photovoltaic module made from natural fibres.
NG : We integrate all the data collected into our generic environmental analysis tool to compare them with existing data on standard glass modules. To then carry out a full life cycle analysis, we need a quantity of good quality data, representative on an industrial scale. It can take several months to get them for each “recipe”.
That said, we already know that no material considered increases the environmental impact – which is not always the case, even for a material of natural origin, the transformation of which can sometimes prove harmful. According to our initial analyses, the environmental gain varies, depending on the recipes, between 5 and 15%, on all of the 17 environmental criteria recommended by Europe. We haven’t noticed any performance losses either, which is crucial given the higher price of this type of material, which is not yet in mass production.
AE: What other part of a solar panel could be eco-designed?
NG : Replacing or removing the aluminum frame is an undeniable additional step to reduce the environmental footprint of the panels.
AE: Is it possible to push eco-design to the limit, without impacting the industry?
DC : Above all, we seek to deploy solutions that do not lead to development losses. The objective of the ITE Ines.2S is to implement a circular economy model and to integrate solar energy in a massive way, while occupying as little space as possible and reducing its impact on the environment. environment. For this, our mission is to guide the technological choices to direct the production of photovoltaic panels in the right direction. The enrichment of our database is primarily intended to help engineers in this area.
Article published on April 22, 2022