Latest Impact Factor figures from Elsevier's Energy Journals
We are delighted to inform you that the 2011 Impact Factor figures show, once again, a strong performance for almost all of Elsevier's Energy journals.
Thanks to the contributions of our authors, reviewers and editors, we publish 13 out of the top 20 journals in terms of Impact Factors, and 18 out of the top 20 journals in terms of total cites, with the Journal of Power Sources, Bioresource Technology and the International Journal of Hydrogen Energy ranking 1st, 2nd and 3rd respectively.
Further highlights from this year’s Impact Factors include significant increases for Progress in Energy and Combustion Science (+ 37%), Applied Energy (+31%), Renewable and Sustainable Energy Reviews (+31%), and the International Journal of Greenhouse Gas Control (+25%).
Also noteworthy are Energy for Sustainable Development and Utilities Policy, both receiving their first Impact Factors of 1.625 and 0.804 respectively.
Further highlights include:
 | Progress in Energy and Combustion Science | |
| 2010 Impact Factor WAS 10.3622011 Impact Factor NOW 14.220 |  | |
 | Renewable and Sustainable Energy Reviews | |
| 2010 Impact Factor WAS 4.5672011 Impact Factor NOW 6.018 |  | |
 | International Journal of Greenhouse Gas Control | |
| 2010 Impact Factor WAS 4.0742011 Impact Factor NOW 5.111 |  | |
 | Applied Energy | |
| 2010 Impact Factor WAS 3.8882011 Impact Factor NOW 5.106 |  | |
Calculating Impact Factors
WHAT IS AN IMPACT FACTOR?
The journal impact factor is a measure of the frequency with which the average article in a journal has been cited in a particular year. The impact factor helps you evaluate a journal's relative importance, especially when you compare it to others in the same field. The impact factor is calculated by dividing the number of citations in the current year to items published in the two previous years by the total number of items published in the two previous years.
| Cites in 2011 to items published in: | 2010 2009 Sum |
= 258 = 199 = 457 |
| Number of items published in: | 2010 2009 Sum |
= 116 = 71 = 187 |
| Calculation: | Cites to recent items | 457 | = 2.444 |
| Number of recent items | 187 |
The 2011 Impact Factor for Journal X is 2.444
Journal Performance Measurements
Journal performance measurements offer a systematic, objective means to critically evaluate journals, and several indicators are available.
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