Large-scale global use of new renewable energy sources (RES) necessitates massive physical resources. Present study shows that more than 99.5% of the materials needed in new RES systems are basic construction materials and metals abundantly available. Special elements may constitute future bottle-necks in some PV technologies. The extra financial resources needed over traditional energy to achieve a breakthrough in PV and wind power range from 100 to 500 billion $ for a period of 20-30 years influenced by technology progress and speed of penetration, but in solar heating much less. This upfront support could be paid back within 15-25 years later through cheaper and cleaner energy. Compared to nuclear power the resource numbers estimated are of the same order of magnitude. (c) 2006 Elsevier Ltd. All rights reserved.