Hydrogen is today the most feasible energetic vector of renewable energy to replace non-renewable resources for several reasons. Hydrogen allows a high efficiency conversion in water electrolysis, higher than 70-80%, and enables an immediate recycle form. It can be converted into electricity in fuel cells at an efficiency around 50-70%. Brazil has an unexplored photovoltaic potential, mainly in its Northeast region. This region has an average insolation of 1800 kW m(-2) yr, which means 80% of the Saudi Arabia average, 2400 kWh m(-2) yr. The possibilities of producing electricity and electrolytic hydrogen by using photovoltaic energy is attractive if the use of secondary hydroelectricity from the Northern region as a compensation form to increase the supply reliability during the low solar radiation exposure period, is considered. This paper is a comparative study about the possibilities of Brazil to producing and exporting liquefied hydrogen in similar conditions the HYSOLAR project. Competitive advantages are likely to be developed for the hydrogen exportation produced from photovoltaic energy linked to secondary hydroelectricity. However Brazil require international cooperation to develop its photovoltaic potential and to adopt modern technologies to produce hydrogen for exportation. (C) 1998 International Association for Hydrogen Energy.239735739