REGIONAL AND GLOBAL EXERGY AND ENERGY EFFICIENCIES

We present estimates of global energy efficiency by applying second-la w (exergy) analysis to regional and global energy balances. We use a u niform analysis of national and regional energy balances and aggregate these balances first for three main economic regions and subsequently into world totals. The procedure involves assessment of energy and ex ergy efficiencies at each step of energy conversion, from primary exer gy to final and useful exergy. Ideally, the analysis should be extende d to include actual delivered energy services; unfortunately, data are scarce and only rough estimates can be given for this last stage of e nergy conversion. The overall result is that the current global primar y to useful exergy efficiency is about one-tenth of the theoretical ma ximum and the service efficiency is even lower.