The work performed since the beginning of the project and main results achieved are summarised in the following points:
• Optimisation of processes for highly efficient kesterite solar cells: Main results obtained include the demonstration of MGL solar cell with 14% active area certified efficiency (10.2% total area efficiency) and microcrystalline thin film solar cell with 14.1% total area efficiency (with estimated 15.1% efficiency after correction of reflection losses, in line with the current world record certified 15.1% efficiency);
• Encapsulation, durability and reliability: Non encapsulated devices show good stability results in different technologies (including MGL and thin film microcrystalline cells) and substrates (glass, steel) with best devices from each technology showing degradations below 5% after 1000 hours in dry environment. Epoxy formulation and primers have been developed and the large scale mass production of encapsulants has been achieved for the encapsulation of module prototypes;
• Modules fabrication: Main results include: i) the successful transfer of thin film microcrystalline processes from glass substrate to flexible (steel) substrate; ii) the development and demonstration of all solution processes front contact achieving < 10W/sq resistance, transparency > 85% and material costs reduction > 50%; iii) the demonstration of first successful up scaled production of a CBD front contact deposited on 2000 x 20 cm2 module, with the achievement of an homogeneous front contact coating with a sheet resistance of 6.06 Ω/sq. and standard deviation of 0.42 Ω/sq. over the full length of 20cm; and iv) the demonstration of flexible MGL modules with a cell to module efficiency gap of 5.1% and a flexible microcrystalline monolithically interconnected thin film modules with a cell to module gap of 22.6%;
• Demonstration in 2 business scenarios: BIPV and PIPV: Activities developed have included the design, development and production of 2 BIPV product demonstrators (modular façade element with PV lamellas, solar tiles) and 2 PIPV product demonstrators (solar bench ligtshroom). For each of the products, two prototypes have been produced integrating MGL and thin film microcrystalline modules, and the products have been demonstrated at real world outdoor operational conditions corresponding to AYESA (Seville, Spain) and Sunplugged (Innsbruck, Austria) test sites. Analysis of collected data has allowed to demonstrate the viability of the BIPV and PIPV demonstrators at real world operational conditions, with estimated electricity generation in line with the proposed product applications;
• Cost analysis, recycling, LCA and societal acceptance: Main results achieved include: i) Environmental analysis of processes, with the development of LCA analysis of both monograin and thin film microcrystalline technologies and benchmark with alternative thin film technologies; ii) the development of LCC model. Sensitivity analysis of electricity costs produced from the assessed solar modules to changes in module efficiency shows that module efficiency of kesterite thin film modules would need to be approximately 12% to compete with CIGS, whereas monograin modules would need an efficiency of around 10%., close to the estimated values according to the project results; iii) Definition of the better routes and processes for kesterite solar modules recovery, including demonstration of the recycling processes at both lab and pilot plant level, with the achievement of global recovery yields in the rabge 93% - 98%. This has included the successful recovery of the kesterite grains in the MGL modules and of the stainless steel based foil in the thin film microcrystalline modules, with the achievement of global recovery yields in the range 96% - 98%.
• Dissemination and communication activities: These activities have included: i) the implementation of project identity and online communication channels, with the launching at the early stage of the project of the project web site and the production of project leaflets and a promotional video, and the production of 5 Newsletter issues that have been distributed through the project website and social media channels; ii) the launching of a news release campaign at the initial stage of the project; and iii) the development of an intense scientific dissemination campaign including participation in international conferences & workshops (with 126 contributions at more relevant conferences, including 19 invited contributions), and publication of 35 papers in relevant high impact scientific journals;
• Exploitation activities have included: i) the identification of Custom-Art exploitable results. Definition of most appropriate strategy for each of the partners in relation to patents and intellectual property has been studied, following the recommendations of the European IPR Helpdesk document to maximize their impact; and ii) the implementation of a business model according to Business Model Canvas methodology for BIPV and PIPV products where the value proposition of the products is defined as well as a marketing plan generating a customer model and value map of the products.
