WAFER-BASED CRYSTALLINE SILICON MODULES AT 1 €/WP: FINAL RESULTS FROM THE CRYSTALCLEAR INTEGRATED PROJECT

Abstract

SCHOTT Solar, DE.E-mail: sinke@ecn.nl, Project website: www.ipcrystalclear.info.ABSTRACT: CrystalClear was an EU co-financed Integrated Project aimed at developing technology for wafer-based silicon solar modules at 1 € per watt-peak manufacturing costs and a strongly improved environmental profile. The project consortium has selected a number of technologies that potentially comply with these aims as well as research that serves as basis for further developments (beyond the project aims). These technologies have been demonstrated in the form of demonstrators, i.e. full-size modules featuring all innovations necessary to comply with the aims. The project has shown that wafer-based multicrystalline-silicon solar modules can be produced at 1 € per watt-peak at a world-record efficiency of 16% and an energy pay-back time of less than 2 years in Southern Europe.Keywords: back contact, c-Si, cost reduction, manufacturing and processing, module manufacturing, multicrystalline silicon, silicon solar cell, LCA, energy pay-back time.1 GENERAL PROJECT OVERVIEWCrystalClear [1-4] was a 5½-year Integrated Project carried out in the 6th Framework Program of the EU. It started in January 2004 and was finished in June 2009. The project was a joint effort of a consortium of 16 European companies, research institutes and university groups involved in wafer-based crystalline silicon PV technology.Companies: BP Solar (ES), Deutsche Cell (DE), Deutsche Solar (DE), Isofoton (ES), Photowatt (FR), REC (NO), REC Wafer Norway (NO), SCHOTT Solar (DE), SolarWorld Industries (DE).Universities: Utrecht (NL), Konstanz (DE), UPM-IES (ES);Research institutes: InESS-CNRS (FR), ECN (NL, project coordinator), FhG-ISE (DE), IMEC (BE).Within CrystalClear an average of over 50 researchers from 6 European countries have worked together.The project aims have been divided in three main blocks.1. Availability of innovative manufacturing technologies which allow solar modules to be produced at a cost of 1 €/watt-peak (which is a reduction by more than 50% compared to state-of-the-art at the start of the project). This objective is very ambitious, but essential to get world-class technology. Manufacturing cost reduction is essential to bring prices of modules and turn-key complete systems down.2. Improved environmental profile of solar modules by reduction of materials consumption, replacement of undesired materials and designing for recycling. This will strengthen the position of solar energy as a clean and sustainable alternative to conventional electricity generation.3. Enhanced applicability of modules by tailoring to customer needs and by improving product lifetime and reliability. Since solar modules will be used in very different situations (e.g. on buildings) flexibility of use is crucial. Assured quality is a prerequisite for large-scale, professional use.The CrystalClear project has tackled all aspects from the raw materials up to the completed solar module. Key activities concerned:• strongly reducing the consumption of expensive materials (especially silicon, but also others) as well as introducing the use of cheaper materials;• increasing the electricity output of solar modules;• developing highly automated, high-throughput, low-cost manufacturing processes;• screening materials, processes and products in relation to sustainability and suitability for large-scale use.Since many combinations of options for cell and module design, processing and materials potentially fulfill the project aims, a selection of 6 distinctly different overall technologies has been developed, underlining the many faces of wafer-based silicon PV and the variety of approaches found within the industry. The feasibility of these technologies to comply with the projects aims has been verified by detailed cost and environmental analyses. CrystalClear has chosen technologies which might be demonstrated as full-scale modules already at the end of the project as well as technologies which stillneed to be developed further after the project.The project has been organized in Subprojects (SPs), covering the parts of the value chain as well as integrating aspects (environmental analyses, cost calculations, etc.), see Figure 1. In the following, the final project results achieved are summarized per Subproject: