| United States Department of Energy |
12,284 |
| BP British Petroleum |
3,519 |
| CH2M HILL Companies, Ltd. |
2,469 |
| Duke Energy Corporation |
2,131 |
| Johnson Controls, Inc. |
1,579 |
| Southern Company |
1,525 |
| Exelon Corporation |
1,445 |
| Entergy Corporation |
1,410 |
| Halliburton Company |
1,409 |
| Archer-Daniels-Midland Company |
1,352 |
| Schlumberger Limited |
1,305 |
| PG&E Corporation |
1,069 |
| El Paso Corporation |
1,055 |
| Praxair, Inc. |
968 |
| Energy Future Holdings |
932 |
| Valero Energy Corporation |
912 |
| The Williams Companies, Inc. |
754 |
| CenterPoint Energy, Inc. |
739 |
| Devon Energy Corporation |
723 |
| Occidental Petroleum Corporation |
699 |
| Public Service Enterprise Group Incorporated |
695 |
| Pacific Northwest National Laboratory (PNNL) |
692 |
| Progress Energy Inc. |
691 |
| Ameren Corporation |
688 |
| Cameron International Corporation |
664 |
| AES Corporation |
596 |
| Kinder Morgan, Inc. |
590 |
| Hess Corporation |
583 |
| Weatherford International Ltd. |
561 |
| Apache Corporation |
550 |
| Sunoco, Inc. |
525 |
| Arizona Public Service Company |
513 |
| Florida DOT |
508 |
| Tesoro Corporation |
484 |
| Reliant Energy |
479 |
| IHS Inc. |
477 |
| ONEOK, Inc. |
457 |
| Smith International, Inc. |
454 |
| Atmos Energy Corporation |
441 |
| Evonik Degussa Corporation |
424 |
| KBR, Inc. |
422 |
| General Atomics |
400 |
| BJ Services Company |
390 |
| SRP Salt River Project |
383 |
| Aker Solutions |
383 |
| ICF International, Inc |
381 |
| Petro-Canada |
362 |
| Premier, Inc. |
362 |
| CMS Energy Corporation |
362 |
| Wood Group |
360 |
| Nexen Inc. |
343 |
| Dynegy Inc. |
336 |
| Southwest Power Pool |
302 |
| McJunkin RedMan Corporation |
294 |
| Platts |
286 |
| SCS Engineers |
280 |
| British Columbia Transmission Corporation |
277 |
| Noble Energy, Inc. |
251 |
| Direct Energy Marketing Limited |
235 |
| Briggs and Morgan, P.A. |
232 |
| TNP Enterprises, Inc. |
228 |
| M-I SWACO |
227 |
| Pride International, Inc. |
217 |
| Areva NC Inc |
215 |
| Suncor Energy Inc. |
214 |
| Nabors Drilling USA, LP |
213 |
| National Energy Board |
208 |
| CONSOL Energy Inc. |
194 |
| Hatch Ltd. |
190 |
| Caterpillar Solar Turbines |
187 |
| Day & Zimmermann |
185 |
| National Rural Electric Cooperative Association |
185 |
| M. A. Mortenson Company |
176 |
| Talisman Energy Inc. |
176 |
| American Agip Co., Inc. |
176 |
| AREVA T&D Inc |
176 |
| Irving Oil Limited |
173 |
| Scottish & Southern Energy P.L.C. |
171 |
| Sasol North America Inc. |
171 |
| Wilson |
168 |
| Air Systems Inc |
165 |
| Energy Transfer Partners, L.P. |
164 |
| Southwire Company |
163 |
| Union Gas Limited |
162 |
| Austin Industries |
158 |
| Samson Investment Company |
156 |
| HAZCO |
155 |
| Plains Exploration |
153 |
| Forest Oil Corporation |
149 |
| RWD Technologies, Inc. |
149 |
| American Transmission Company LLC |
145 |
| Great River Energy |
138 |
| Philip Services Corporation (PSC) |
130 |
| Louis Dreyfus Corporation |
130 |
| Langan Engineering and Environmental Services, Inc |
128 |
| Ergon, Inc. |
128 |
| S&C Electric Company |
126 |
| Flying J Inc. |
125 |
| Dermatology Associates |
125 |
| Team Fishel |
122 |
| STP Nuclear Operating Company |
120 |
| Toronto Hydro Corporation |
117 |
| ATC Group Services Inc. |
116 |
| Alpha Technologies |
112 |
| Wachter Corp |
108 |
| Cheniere Energy, Inc. |
107 |
| Denbury Resources Inc. |
106 |
| Swift Energy Company |
104 |
| Vermont Energy Investment Corporation |
103 |
| Edison Electric Institute |
101 |
| East Kentucky Power Cooperative |
101 |
| Nuclear Energy Institute |
100 |
| Nexant, Inc. |
95 |
| Cameco Corporation |
94 |
| Ontario Centres of Excellence Inc. |
91 |
| Cabot Oil & Gas Corporation |
90 |
| Babcock Power, Inc. |
89 |
| International Resources Group Ltd |
89 |
| Crosstex Energy, L.P. |
87 |
| Plug Power Inc. |
85 |
| Veolia Energy North America |
85 |
| Global Industries, Ltd. |
84 |
| Gas Technology Institute |
83 |
| Luvata Grenada LLC |
82 |
| Iberdrola Renewables |
81 |
| Eugene Water |
80 |
| Petrobras-USA |
80 |
| Converteam Inc |
79 |
| Clark Nexsen Architecture |
78 |
| Subsea 7 |
77 |
| Nsf International |
77 |
| Alberta Utilities Commission |
75 |
| Paradigm Geophysical |
74 |
| American Precision Industries, Inc. |
73 |
| EnergySolutions, Inc |
73 |
| Evergreen Solar, Inc. |
73 |
| Aecon Group Inc. |
72 |
| Petrohawk Energy Corporation |
71 |
| Affiliated Engineers, Inc. |
70 |
| Rowan Companies, Inc. |
69 |
| Colonial Pipeline Company |
68 |
| Matrix Service Company |
67 |
| Board of Public Utilities of Kansas City, Kansas |
67 |
| Trinity Consultants |
66 |
| Energy Advantage Inc |
65 |
| ENGlobal Corporation |
64 |
| Canadian Commercial Corporation |
63 |
| Woodside Natural Gas |
63 |
| EPCO, Inc. |
63 |
| Hydril Pressure Control |
62 |
| Helmerich & Payne |
62 |
| TME Inc |
62 |
| Christopher A. Joseph |
62 |
| R.G. Vanderweil Engineers, Inc. |
61 |
| Lansing Board of Water and Light |
61 |
| Versar, Inc. |
59 |
| Independent Electricity System Operator |
58 |
| Comverge, Inc. |
58 |
| Sunflower Electric Power Corporation |
58 |
| Triten Corporation |
57 |
| Hunting Energy Svc Lp |
57 |
| Linn Energy LLC |
57 |
| Delta Environmental Consultants, Inc. |
56 |
| Pike Electric, Inc. |
56 |
| First Wind |
55 |
| Energy Intelligence Group |
54 |
| Seismic Exchange Inc |
54 |
| Institute of Nuclear Power Operations (INPO) |
53 |
| Biological Research |
53 |
| Bill Barrett Corporation |
53 |
| GCIC - Gulf Coast Ignition Corp |
53 |
| Merit Energy Company |
52 |
| Arctic Slope Regional Corporation |
52 |
| MSW Managment Magazine |
51 |
| Continental Resources, Inc. |
51 |
| Total Safety |
51 |
| Morrison Hershfield |
51 |
| SolArc |
50 |
| Direct Energy Business |
50 |
| Northern Power Systems, Inc. |
49 |
| Origin Energy Shops |
48 |
| Sproule Associates Limited |
48 |
| (OPIS) Oil Price Information Service |
47 |
| Flint Energy Service |
47 |
| BI Nutraceuticals |
47 |
| Williston Basin Interstate Pipeline Company |
46 |
| Public Works Commission of The City of Fayetteville |
46 |
| Motor & Equip.Manufacturers Assoc. |
46 |
| Cpower, Inc. |
46 |
| Groupe Tecsult |
45 |
| Alameda County Water District |
45 |
| Quadrem |
45 |
| Big Rivers Electric Corp. |
45 |
| Citation Oil & Gas Corp. |
45 |
| Country Energy |
45 |
| C-FER Technologies |
44 |
| Fuscoe Engineering |
44 |
| National Association of Regulatory Utility Commissioners |
43 |
| Edison Welding Institute |
43 |
| Petroleum Geo-Services |
43 |
