LOW-COST INDUSTRIAL TECHNOLOGIES OF CRYSTALLINE SILICON SOLAR-CELLS

Approximately 2 billion people, mainly in Third World countries, are n ot connected to an electric grid. The standard, centralized grid devel opment is too expensive and time consuming to solve the energy demand problem. Therefore, there is a need for decentralized renewable energy sources. The main attractiveness of solar cells is that they generate electricity directly front sunlight and can be mounted in modular, st and-alone photovoltaic (PV) systems. Particular attention is paid in t his paper to crystalline silicon solar cells, since bulk silicon solar -cell (mono and multi) modules comprise approximately 85% of all world wide PV module shipments. Energy conversion efficiency as high as 24% has been achieved an laboratory, small-area monocrystalline silicon ce lls, whereas the typical efficiency of industrial crystalline silicon solar cells is in the range of 13-16%. The market price of PV modules remains for the last few pears in the range of $3.5-4.5/watt peak (Wp) . For the photovoltaic industry the biggest concern is to improve the efficiency and decrease the price of the commercial PV modules. Effici ency-enhancement techniques of commercial cells are described in detai l. Adaptation of many high-efficiency features to industrially fabrica ted solar cells resulted in efficiencies above 17% for multicrystallin e and above 18% for monocrystalline silicon solar cells. The latest st udy shows that increasing the PV market size ton ard 500 MWp/y and acc ounting for realistic industrial improvements can lead to a drastic PV module price reduction down to $1/Wp.