Top journals in energy and fuels by impact

Rank	Impact 1981-2007	Impact 2003-07	2007 impact factor
1	Chem Phys Carbon (42.88)	Prog Energ Combust (9.22)	Prog Energ Combust (5.)
2	Prog Energ Combust (39.20)	Chem Phys Carbon (9.00)	Renew Sust Energ Rev (3.77)
3	AAPG Bulletin (15.80)	J Power Sources (4.82)	Fuel Cells (3.)
4	Combustion and Flame (13.41)	Prog Photovoltaics (4.37)	Bioresource Technol
5	Ann Rev Energ Envir (11.38)	Combustion and Flame (3.82)	J Power Sources (2.81)
6	Fuel (9.76)	Proc Combustion Inst (3.81)	Int J Hydrog Energ (2.73)
7	Bull Cent Rech Elf (9.07)	Bioresource Technol (3.76)	Proc Combustion Inst (2.65)
8	Combustion Sci Tech (8.89)	Sol Energ Mat Sol (3.66)	Combustion and Flame (2.18)
9	J Power Sources (8.87)	Int J Hydrog Energ (3.35)	Prog Photovoltaics (2.18)
10	Energy & Fuels (8.84)	Biomass & Bioenergy (3.24)	Sol Energ Mat Sol (2.00)

The above table compares the citation impact of journals in a given field as measured over three different time spans. The right-hand column ranks journals based on their 2007 “impact factor”, as enumerated in the current edition of Journal Citation Reports®. The 2007 impact factor is calculated by taking the number of all current citations to source items published in a journal over the previous two years and dividing by the number of articles published in the journal during the same period – in other words, a ratio between citations and recent citable items published. The rankings in the other two columns show impact over longer periods, based on figures from Journal Performance Indicators. In these columns, total citations to a journal’s published papers are divided by the total number of papers that the journal published, producing a citations-per-paper impact score over a five-year period (middle column) and a -year period (left-hand column).