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FEATURED ANALYSIS, November/December 2008

Energy Gauge: Who Exactly Is In Power?
by Christopher King, Editor

Few topics these days are as pervasive and pressing as the discussion about energy: how it immediately affects matters both economic and political, and how the search for new and alternative technologies must be a priority. Accordingly, Science Watch® turns its attention to energy as a focus of scientific research.

To identify highly cited energy research of recent years, Science Watch turned to the "Energy & Fuels" category in which journals are covered in the Science Citation Index, part of the Thomson Reuters Web of Knowledge. This population of 94 specialty journals produced roughly 100,000 papers indexed by Thomson Reuters between 1998 and 2008. From that body of research, Science Watch identified the most-cited institutions, authors, and journals.

Most-Cited Journals
in Energy & Fuels, 1998-2008

(Ranked by citations to papers
published and cited between
1998 and 2008)


1 Journal of Power Sources 71,741
2 Bioresource Technology 26,617
3 Fuel 19,247
4 Solar Energy Mater. & Solar Cells 18,063
5 Energy & Fuels 17,650
6 Combustion and Flame 17,448
7 Intl. J. of Hydrogen Energy 16,186
8 Energy Conversion & Management 10,051
9 Biomass & Bioenergy 8,234
10 Energy Policy 8,168
11 Proc. of the Combustion Institute 7,845
12 Fuel Processing Technology 7,205
13 Solar Energy 6,979
14 Applied Thermal Engineering 6,288
15 AAPG Bulletin 6,046
SOURCE: Thomson Reuters Science Citation Index.

The two tables below present institutions ranked according to two separate measures: the first table (1a), by total citations to Energy & Fuels papers published and cited during the 1998 to 2008 period; and, the second table (1b), by impact, or citations per paper, among those institutions that published at least 100 papers in the category during the 11-year span. Highly cited authors and journals are featured in the bottom table (2).

Among institutions ranked by total citations, none surpasses Sandia National Laboratories, with more than 4,100 citations to its 395 papers, although another U.S. Department of Energy installation, the National Renewable Energy Laboratory (NREL), of Golden, Colorado, is not far behind. Along with these and other U.S. national facilities, the total-citations ranking features comparable government institutions representing other nations, including Spain's Consejo Superior de Investigaciones Cientificas (CSIC), France's Centre National de le Recherche Scientifique (CNRS), and Japan's National Institute of Advanced Industrial Science and Technology (AIST), along with the national science academies of China and Russia.

Nevertheless, in the midst of these large national institutions, a number of universities also make strong showings in the total-citations column, notably Pennsylvania State University, Imperial College London, and Princeton University.

Princeton, in fact, winds up atop the impact ranking, with an average of 13 citations to its 210 papers indexed in the Energy & Fuels category since 1998. Helping to anchor Princeton's standout performance are two featured names in the author table: the late Supramaniam Srinivasan, who contributed to highly cited surveys of fuel-cell research; and C.K. Law, who has published prolifically on aspects of combustion.

Just behind Princeton, a solid impact score is also posted by the Jülich Research Centre (Forschungszentrum Jülich), a German national laboratory, thanks to its highly cited papers on photovoltaics, methanol fuel cells, and other topics.

Among authors, Ayhan Demirbas of Karadeniz Technical University in Trabzon, Turkey, collected nearly 1,900 citations on an output that exceeded 200 papers. (Of course, a prolific output by itself is no guarantee of high citations; besides Demirbas, eight other authors fielded more than 200 papers in this survey, but none of these names garnered more than 15 total citations.) Papers to which Demirbas contributed primarily discuss biofuels, along with broader aspects of energy policy in Turkey.

In the above table to the right, the Journal of Power Sources distinguishes itself with more than 71,000 collective citations to 7,705 papers indexed by Thomson Reuters since 1998—a total more than twice that of the next journal in the ranking.

Overall, the most-cited paper in this survey, from 1999, reports the achievement of 18.8% conversion efficiency in a thin-film solar cell (M.A. Contreras, et al., Prog. Photovoltaics, 7: 311-6, 1999). The paper's current citation total of 465 considerably boosted the tallies of four authors featured here (all affiliated with the NREL at the time): Miguel Contreras, Rommel Noufi, Kannan Ramanathan, and Falah Hasoon.

Christopher King is the Editor of the Science Watch® Newsletter, Thomson Reuters.

Table 1a    

Energy & Fuels:
Institutions Ranked by Citations
(among those that published = 100 papers, 1998-2008)


1 Sandia National Labs 4,147
2 Natl. Renewable Energy Lab 3,773
3 CSIC (Spain) 3,678
4 Chinese Academy of Sciences 3,541
5 Indian Institutes of Technology 3,166
6 Pennsylvania State University 2,870
7 Imperial College London 2,823
8 Princeton University 2,744
9 University of Illinois 2,647
10 Tohoku University 2,609
11 CNRS (France) 2,598
12 AIST (Japan) 2,482
13 Argonne National Lab 2,438
14 Lawrence Berkeley National Lab 2,331
15 Technical University of Denmark 2,278
16 MIT 2,215
17 Russian Academy of Sciences 2,175
18 Fraunhofer Institute Solar Energy Systems 2,099
19 University of Leeds 2,062
20 Stanford University 1,990
21 Tsinghua University 1,932
22 Chalmers University of Technology, Sweden 1,904
23 University of Kentucky 1,797
24 University of Sydney 1,764
25 University of New South Wales 1,722

SOURCE: Thomson Reuters Science Citation Index.


Table 1b    

Energy & Fuels:
Institutions Ranked by Citation Impact
(among those that published = 100 papers, 1998-2008)


1 Princeton University 13.07
2 Jülich Research Centre, Germany 12.76
3 Natlional Renewable Energy Lab 11.13
4 Cornell University 11.10
5 University of Victoria 11.03
6 Argonne National Lab 10.79
7 Sandia National Labs 10.50
8 North Carolina State University 10.46
9 Yale University 10.41
10 University of Sydney 9.75
11 Fraunhofer Institute Solar Energy Systems 9.72
12 MIT 9.63
13 United States Army 9.22
14 University of Ulster 8.94
15 Uppsala University 8.76
16 University of California, Berkeley 8.61
17 Karadeniz Technical University, Turkey 8.53
18 Oak Ridge National Lab 8.48
19 University of Queensland 8.34
20 University of Illinois 8.32
21 Yonsei University 8.13
22 University of Delaware 8.09
23 Paul Scherrer Institute, Zurich 8.06
24 University of Kentucky 8.06
25 Korea Institute of Science & Technology 8.05

SOURCE: Thomson Reuters Science Citation Index.


Table 2:    

Highly Cited Authors in Energy & Fuels, 1998-2008
(Ranked by total citations)






1 Ayhan Demirbas Karadeniz Tech. U., Turkey Biofuels 245 1,891
2 Rafael Kandiyoti Imperial College London Coal Derivatives 111 1,045
3 Rommel Noufi Natl. Renewable Energy Lab Solar Cells 17 959
4 Imbrahim Dincer U. Ontario Inst. Technol. Fuel Cells 94 910
5 Kim Dam-Johansen Tech. Univ. Denmark Combustion 48 877
6 Kannan Ramanathan Natl. Renewable Energy Lab Solar Cells 10 874
7 Falah Hasoon Natl. Renewable Energy Lab Solar Cells 9 871
8 Miguel Contreras Natl. Renewable Energy Lab Solar Cells 8 843
9 Arif Hepbasli Ege University, Turkey Technology & Policy 116 794
10 Supramaniam Srinivasan* Princeton University Fuel Cells 8 780
11 Khalil Amine Argonne Natl. Lab Battery Technology 41 773
12 Poonam Nigam University of Ulster Bioconversion 14 751
13 Chung K. Law Princeton University Combustion 86 744
14 Masaki Yoshio Saga University Battery Technology 44 740
15 Charles K. Westbrook Livermore Natl. Lab Combustion 23 735
16 Doron Aurbach Bar-Ilan University, Israel Energy Storage 40 721
17 Kamil Kaygusuz Karadeniz Tech. U. Technology & Policy 81 703
18 Chao-Yang Wang Pennsylvania State Univ. Fuel Cells 39 702
19 James C. Hower University of Kentucky Coal Geology 83 700
20 Alan A. Herod Imperial College London Coal Derivatives 63 690
21 Martin A. Green Univ. New South Wales Solar Cells 63 674
22 William J. Pitz Livermore Natl. Lab Kinetics/Combustion 21 671
23 Jürgen O. Besenhard† Graz Univ. Technol. Battery Technology 32 665
24 Robert W. Bilger University of Sydney Combustion 36 652
25 Martin Winter University of Münster Battery Technology 26 647
SOURCE: Thomson Reuters Science Citation Index. *Deceased 2004† Deceased 2006

Christopher King is the Editor of the Science Watch® Newsletter, Thomson Reuters.

Keywords: Energy, energy research, energy and fuels, solar cells, fuel cells, combustion, Sandia National Laboratories, National Renewable Energy Laboratory, Ayhan Demirbas.

Analyses : Featured Analyses : Energy Gauge: Who Exactly Is In Power?
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