Classification and performance analysis of primary energy consumers during 1980–1999 Volkan S ß . Ediger * ,1 Cumhurbas ßkanlı  gı, C ß ankaya, 06689 Ankara, Turkey Received 18 November 2002; accepted 12 May 2003 Abstract Five primary energy consumer classes, namely Super, Major, Big, Medium and Small, are proposed, depending on the polymodal characteristics of the frequency distribution curve of their share of the total. Thetotalprimaryenergyconsumptionanditsannualadditionsdecrease,whereastheratesincreasesteadily fromtheSupertotheMediumconsumers.Sincethefrequencydistributionhistogramofadditionalprimary energyconsumptionsoftheMediumandaboveconsumersduring1980–1999isatypicalbellshapedcurve, the additional amounts and rates are used together to evaluate the performance levels of the countries in both parameters. The most successful countries are the USA, China, South Korea, Thailand, India, Indonesia, Taiwan, Turkey and Iran. The reason why the Super consumer USA and the Major consumer China are the biggest energy markets is because they are the first two biggest economies in the world. The success of the developing Asian countries is mostly related to their economic ties with the Super consumer USA. Among the other emerging markets, TurkeyÕsprimaryenergydemandhasgrownmorerapidlythan that of Iran and is expected to continue growing in the future. The emerging Medium and Big consumer markets will continue to play a significant role in the worldÕs energy sector during the first two decades of the 21st century. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: Primary energy; Consumer classes; Market performances 1. Introduction RegionaldistributionoftheworldÕsprimaryenergyconsumptionhasneverbeenuniforminthe past. For instance, while North America consumes around 30% of the worldÕs total primary Energy Conversion and Management 44 (2003) 2991–3000 www.elsevier.com/locate/enconman * Address: Mutlukoy 7 Sokak No. 25, 06530 Ankara, Turkey. Tel.: +90-312-470-2209; fax: +90-312-428-3905. E-mail address: ediger@tccb.gov.tr (V.S ß. Ediger). 1 Also teaches at the Geological Engineering Department of the Middle East Technical University in Ankara. 0196-8904/03/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0196-8904(03)00102-X