InnoModu: Lead-free modules with low silver content and innovative busless cell grid Jörg Scheurer, Applications Engineering Polytec PT GmbH 76337 Waldbronn / Germany
Initiator and project coordinator: Dr. Michael Schwark, Austrian Institute of Technologies Energy Department, Business Unit Photovoltaic Systems 1210 Vienna / Austria Submitted by 10/2013 in the SOLA-ERA.NET transnational calls PV1 and CSP1 as industrial research within the call topic PV1.4 (high-efficient PV modules based on next generation c-si cells)
Project key figures: Project start: 01.10.2014 Project end: 31.03.2016 Total project costs: 809 k Total public funding: 525 k Scientific partners: 2 Industry partners: 5 Five Austrian and two German partners
Project partners: Scientific partner: AIT - Austrian Institute of Technology (Austria) CTR - Carinthian Tech Research AG (Austria) Industry partner: energetica Energietechnik GmbH (Austria) KIOTO Photovoltaics GmbH (Austria) Polytec PT GmbH (Germany) teamtechnik GmbH (Germany) Ulbrich of Austria GmbH (Austria)
Project objectives:
Project objectives:
Project targets: Reduce the share of lead used in a module due to soldering to nearly zero by establishing a gluing technology Drastically minimize the silver content by ~50wt% in solar cells due to replacement of silver paste metallization by electroplating of Ni/Cu Reduce the shadowing of the active cell surface by thinner electroplated finger grids and by using light capturing ribbons (LCR )
WP1 Project Management, Dissemination AIT, CTR, KIOTO General organisation, project lead, financial organisation, organisation of content oriented administration. WP2 Galvanic Process, Finger Design PT, AIT, CTR The next generation of silicon solar cells with galvanic metallization of copper will be developed. WP3 Conductive Glue Formulation PT, AIT, CTR, ULB, TEAM In this work package an innovative electrically conductive gluing process will be performed to get the cells connected lead-free with a high conductivity.
WP4 String Features & Stringing Process TEAM, AIT, PT, ULB In this work package the existing stringing process technology will be modified to be able to handle the glue. Furthermore the necessary string features like materials (cells, ribbon), number of busbars, cell thickness, geometry of ribbon, geometry of string, definition of the variation of the materials, etc. have to be defined and evaluated. WP5 Full process optimization AIT, CTR, KIOTO, PT, TEAM, ULB, ENE The objective is to combine all new designed and developed components (ribbons, adhesives etc.) and processes (galvanic, gluing and stringing process) in order to obtain innovative engineering samples.
Screen printing of ECA s on busbar-less c-si cells glass EVA coated copper ribbon Electrically conductive adhesive (ECA) c-si cell EVA back sheet
Electrically conductive adhesive (ECA) + LCR + ECA-stringer Electrically conductive adhesive of Polytec PT Source: www.teamtechnik.com LCR ribbon of Ulbrich
Mini-module variations Altogether nine different combinations of one cell mini-modules have been produced within a first trial run Ni/Cu/Ag electroplating was combined with a Ag coated LCR Ni/Cu electroplating was combined with a pure copper LCR Ni/Cu + OSP electroplating was combined with a protected copper LCR Gluing of the ribbons with three different electrically conductive adhesives
Mini-modules: Damp Heat (85/85) Test InnoModu
Bionic Design Approach for Busbars and Fingers Parameter Unit Bionic Std. Enh. Std. front metal contact area cm² 6,81 9,49 6,05 front optically inactive area cm² 7,99 10,63 7,25 front shading mw/cm² 1,49 2,00 1,37 J sc ma/cm² 36,95 36,07 37,19 V oc mv 658,36 656,60 659,06 FF % 78,61 80,33 79,68 Efficiency % 19,12 19,02 19,53 V mpp mv 550,00 560,74 559,50 I mpp A 4,14 4,04 4,16 J mpp ma/cm² 34,77 33,93 34,91 power output mw/cm² 19,11 19,02 19,53 The results show, that the bionic design represents an effective, improved solar cell design, compared to the linear standard design.
SOLAR-ERA.NET: General comments / problems / ideas (from a point of view of SME) Insolvency (under self administration) of one potential partner delayed start of InnoModu due its non funding status. Suspension of funding due to election in Germany in 2013 delayed start of the InnoModu project. Still a quite long approval procedure (joint call to project start), as industry is looking always for a fast realization of R&D ideas. Sometimes unclear where and how (English / German?) proposals have to be submitted: national / international? International program with regional funding has to be approved by each sponsorship organization: one central contact point for approval?
SOLAR-ERA.NET: General comments / problems / ideas (from a point of view of SME) Profi Online (Germany) is a quite helpful tool, to keep the project updated and conform due to the administrative requirements. Project executing organization should keep in mind, that within a SME (e.g. < 20 employee's) technical and administrative work is often done by the same person. Formal aspects of the project are not always so clear / familiar for a SME as for a research institute. In general the SOLAR-ERA.NET program is a good opportunity for SME to come into contact with European industry partners (provider of consumable material provider of manufacturing machines) in order to establish an innovative European PV / solar thermal research network. SOLAR-ERA.NET network: clear listing of all funded projects with all involved industry partners and research institutes is helpful.
Acknowledgment / Project funding This work was performed within the SOLAR-ERA.NET project "InnoModu", which is funded by the: Austria: Climate and Energy Fund and conducted under the Energy Mission Austria program Germany: Federal Ministry for Economic Affairs and Energy (BMWi) and accompanied by Project Management Jülich (PtJ), Forschungszentrum Jülich (FZJ)