Sustainable energy
The average rate of world total primary energy consumption in 1999 was 12.7 terawatts, or 2150 watts per capita. Only about one-third of this energy flow becomes what could be called "useful energy", and the remaining two-thirds are lost in the energy sector or in end-use devices. LEAD has carried out a number of case studies to explore the challenges towards renewable energy sources and creative options that have been implemented around the world.