The 1979 photovoltaic Solar Energy Conference was organi­ zed by the Commission of the European Communities in co - ope­ ration with the Sen at von Berlin and the Institute for Elect- cal and Electronics Engineers.This conference, as the first one held in Luxembourg in 1977, reflected the interest of the Com­ mission in solar energy research and development : within the Commission's R&D programme the photovoltaic part takes one of the largest shares. The presentations.and the discussions of the recent advan­ ces in photovoltaic technology inspire confidence that this tech­ nology in the long run will provide an alternative energy system. The increasing industrial interest is an indication of the ope­ ning of the market, which is a condition for a rapid decrease in cost. I hope that the success of this Conference will be an en­ couragement to all countries to allocate the R&D funds which are necessary to continue the further development of this tech­ nology. I also hope that this Conference contributed to strengthen the international co - operation.