Greenpeace presents a practical proposal of sustainable energy for Brazil. In the "Energy Revolution" report Greenpeace concludes that by harnessing renewable energy and implementing energy efficiency measures enough electricity can be generated to guarantee the economic growth of the country until 2050. As part of the launching of the report, the Greenpeace installed 40 photovoltaic solar panels that must supply 30% to 60% of the daily demand of electricity in the Greenpeace office in São Paulo. The photovoltaic solar technology allows electricity to generate from panels that catch the light of the sun. The panels are connected to the national energy grid, which is not allowed by law in Brazil. Only about 20 systems of this type exist in Brazil as they require a special license to function.