| 1 | Shandong Energy Group CO., LTD | China | Jinan | Shandong Nengyuan Building, No.10777, Jingshi Road, Lixia Distri | Shandong | 250014 | N/A | 1996 | $119,589,574,674 | 512 | N/A | N/A | 370000018019807 |
| 2 | China Energy Engineering CORPORATION LIMITED | China | Beijing | Building 1, Yard A26, Xidawang Road, Chaoyang District | Beijing | 100022 | N/A | 2014 | $60,273,784,583 | 115,916 | N/A | N/A | 100000000045287 |
| 3 | Tokyo Electric Power Company Holdings, Incorporated | Unitedkingdom | Ealing | 13 Elers Road | London | W13 9QA | N/A | 1998 | $57,179,518,290 | 1 | N/A | N/A | FC021425 |
| 4 | State Power Investment CORPORATION LIMITED | China | Beijing | Building 4, No. 28 Financial Street, Xicheng District | Beijing | 100033 | N/A | 2003 | $54,581,289,152 | 120,145 | N/A | N/A | 100000000037730 |
| 5 | Albab Company For General Contracts, LTD. | Iraq | Baghdad | Arasat 29, 30, 929 | N/A | N/A | N/A | 2002 | $49,876,109,700 | 80 | N/A | N/A | 9336 |
| 6 | Shopper Data Group PTY. LTD. | Australia | Sydney | N/A | New South Wales | 2060 | N/A | 2017 | $23,934,511,029 | 201,413 | N/A | N/A | 620576981 |
| 7 | China Power Engineering Consulting Group CORPORATION | China | Beijing | No.65, Ande Road,xicheng Dist. | Beijing | 100120 | N/A | 2003 | $17,860,681,840 | 324 | N/A | N/A | 100000000038154 |
| 8 | Emcor Group, INC. | USA | Norwalk | 301 Merritt 7 | Fairfield | 06851 | emcorgroup.***** | 1966 | $14,566,116,000 | 40,400 | N/A | N/A | 2122022 |
| 9 | Westnetz GMBH | Germany | Dortmund | Florianstr. 15-21 | Dortmund, Stadt | 44139 | iam.***** | 2019 | $9,112,546,436 | 6,140 | N/A | N/A | 44135B30872 |
| 10 | Aksa Kablo Sanayi Ve Ticaret LTD. Sti | Iraq | Duhok | Qazi Mohammad Road 669/2 Kro 29 | N/A | N/A | N/A | 2009 | $9,005,049,240 | 42 | N/A | N/A | 10220 |
| 11 | Abm Industries Incorporated | USA | New York City | 1 Liberty Plz Fl 7 | New York | 10006 | abm.***** | 1909 | $8,359,400,000 | 117,000 | N/A | N/A | 2057350 |
| 12 | Comfort Systems USA, INC. | USA | Houston | 675 Bering Dr Ste 400 | Harris | 77057 | comfortsystemsusa.***** | 1917 | $7,027,476,000 | 18,300 | N/A | N/A | 2693796 |
| 13 | Ge Vernova International LLC | Unitedkingdom | Stafford | C/o UK Grid Solutions Limited | Staffordshire | ST16 1WT | N/A | 1961 | $6,262,662,000 | 421 | N/A | N/A | FC006906 |
| 14 | Quanta Services, INC. | USA | Houston | 2727 North Loop W Ste 100 | Harris | 77008 | quantaservices.***** | 1997 | $6,233,334,000 | 58,400 | N/A | N/A | 2786882 |
| 15 | Electricity Holding Company | Oman | Muscat | Beach Building, Building No. 37 Shatti al Qurum Road No. 2601, O | Muscat Governorate | 116 | N/A | 2002 | $5,083,860,761 | 3,500 | N/A | N/A | 1708457 |
| 16 | Sepcoiii Electric Power Construction CO., LTD. | China | Qingdao | No. 882-1, Tong'An Road, Laoshan District | Shandong | 266035 | N/A | 1991 | $4,965,814,257 | 3,603 | N/A | N/A | 370726018006274 |
| 17 | Kinden CORPORATION | Japan | Osaka | 2-3-41, Honjohigashi, Kita-ku | Ōsaka | 531-0074 | kinden.***** | 1944 | $4,728,118,948 | 14,359 | N/A | N/A | 1120001063033 |
| 18 | Dycom Industries, INC. | USA | West Palm Beach | 300 Banyan Blvd Ste 1101 | Palm Beach | 33401 | dycomind.***** | 1969 | $4,702,014,000 | 15,623 | N/A | N/A | 350469 |
| 19 | Kandenko CO., LTD. | Japan | Minato-ku | 4-8-33, Shibaura | Tōkyō | 108-0023 | N/A | 1944 | $4,505,680,928 | 10,558 | N/A | N/A | 9010401006818 |
| 20 | Exeo Group, INC. | Japan | Shibuya-ku | 3-29-20, Shibuya | Tōkyō | 150-0002 | N/A | 1954 | $4,498,532,332 | 17,260 | N/A | N/A | 3011001031955 |
| 21 | China Everbright Environment Group LIMITED | Hongkong | Hong Kong | Rm 2703 27/f Far East Finance Ctr | Central & Western District | N/A | N/A | 1993 | $3,888,789,575 | 269 | N/A | N/A | 01195034 |
| 22 | Mirait One CORPORATION | Japan | Koto-ku | 5-6-36, Toyosu | Tōkyō | 135-0061 | N/A | 1944 | $3,880,084,894 | 17,115 | N/A | N/A | 6010601040090 |
| 23 | National Grid USA Service CO. INC. | USA | Malone | 139 Finney Blvd | Franklin | 12953 | N/A | 2019 | $3,787,755,790 | 1 | N/A | N/A | N/A |
| 24 | Sinohydro Engineering Bureau 8 CORPORATION LIMITED | China | Changsha | No.8 Changqing Rd, Tianxin Dist., | Hunan | 410000 | N/A | 1981 | $3,661,035,078 | 8,504 | N/A | N/A | 430000000039259 |
| 25 | Rauaat Al-Bareq Company For General Contracting LTD | Iraq | Baghdad | House 25 Street 13, District 606 | N/A | N/A | N/A | 2008 | $3,289,613,361 | 36 | N/A | N/A | 5135 |
| 26 | Kyudenko CORPORATION | Japan | Fukuoka | 1-11-1, Tenjin, Chuo-ku | Fukuoka | 810-0001 | N/A | 1944 | $3,178,335,524 | 10,828 | N/A | N/A | 6290001001120 |
| 27 | Ies Holdings, INC. | USA | Houston | 2 Riverway Ste 1730 | Harris | 77056 | ies-co.***** | 1997 | $2,884,358,000 | 9,485 | N/A | N/A | 2764678 |
| 28 | Creacion SA | Honduras | Tegucigalpa | Blvd Suyapa Condominio Metropolis Torre 2 | Francisco Morazán | N/A | N/A | 2010 | $2,849,369,455 | 27 | N/A | N/A | 8019010270963 |
| 29 | Powerchina Sepco1 Electric Power Construction Co.,ltd. | China | Jinan | Building A2-6, Hanyu Jinggu, No. 7000 Jingshi East Road, High Te | Shandong | 250102 | N/A | 1980 | $2,798,007,048 | 3,007 | N/A | N/A | 370000018015164 |
| 30 | Downer Edi Engineering Electrical PTY LTD | Australia | Sydney | Triniti Business Campus 39 Delhi Rd | New South Wales | 2113 | downeredi.***** | 1988 | $2,733,159,000 | 23,000 | N/A | N/A | 007102516 |
| 31 | Powerchina Guizhou Engineering CO., LTD. | China | Guiyang | No.1, Huaxi Middle Road, Nanming District | Guizhou | 550000 | N/A | 1985 | $2,458,618,690 | 2,373 | N/A | N/A | 520000000020275 |
| 32 | Programmed Electrical Technologies LTD | Australia | Melbourne | L 32 727 Collins St | Victoria | 3008 | programmed.***** | 1999 | $2,433,224,508 | 20,476 | N/A | N/A | 089479676 |
| 33 | Mmr Group, INC. | USA | Baton Rouge | 15961 Airline Hwy | East Baton Rouge | 70817 | mmrgrp.***** | 1985 | $2,343,916,699 | 4,000 | N/A | N/A | 34351563D |
| 34 | Guangxi Energy Group CO., LTD. | China | Nanning | Floor ,20, Floor No.19, Floor T1, Gig International Finance Zibe | Guangxi | 530201 | N/A | 2003 | $2,313,278,094 | 130 | N/A | N/A | 450000000006273 |
| 35 | Powerchina Hubei Engineering Co.,ltd. | China | Wuhan | No.1, Xinqiao 4th Road, Jinyinhu Street, Dongxihu District | Hubei | 430040 | N/A | 2014 | $2,254,095,852 | 3,493 | N/A | N/A | 420000000055850 |
| 36 | Power China Hebei Engineering CORPORATION LIMITED | China | Shijiazhuang | No. 107 Tabei Road, Yuhua District | Hebei | 050021 | N/A | 1993 | $2,124,602,230 | 1,956 | N/A | N/A | 130100100003547 |
| 37 | Mmr Constructors, INC. | USA | Baton Rouge | 15961 Airline Hwy | East Baton Rouge | 70817 | mmrgrp.***** | 1985 | $2,104,462,226 | 4,000 | N/A | N/A | 34441227D |
| 38 | Rosendin Electric, INC. | USA | San Jose | 880 Mabury Rd | Santa Clara | 95133 | rosendin.***** | 1919 | $2,057,700,000 | 4,600 | N/A | N/A | 0274896 |
| 39 | Iberdrola Australia (SA) Power Holdings PTY LIMITED | Australia | Sydney | 'Governor Phillip Tower' Level 22 1 Farrer Place | New South Wales | 2000 | nextwavelength.***** | 2019 | $2,014,551,145 | 115 | N/A | N/A | 635702126 |
| 40 | Carso Infraestructura Y Construcción, S.A. De C.V. | Mexico | Miguel Hidalgo | Lago Zúrich No. 245 Edificio Frisco Piso 2 | Distrito Federal | 11529 | N/A | 1999 | $2,009,680,847 | 10,500 | N/A | N/A | CIC991214L94 |
| 41 | L&K Engineering CO., LTD. | Taiwan | Xizhi District | 14f, No. 175, Datong Rd., Sec. 1 | New Taipei City | 221451 | N/A | 1978 | $2,003,792,325 | 480 | N/A | N/A | 12204275 |
| 42 | China Energy Engineering Group Guangdong Power Engineering CO., LTD. | China | Guangzhou | No.2, Hongli Road, Huangpu District | Guangdong | 510000 | N/A | 1986 | $1,979,872,745 | 3,370 | N/A | N/A | 440000000010069 |
| 43 | China Energy Construction Group CO., LTD. | China | Hefei | No. 218, Xiangzhang Avenue, Hightech Development Zone | Anhui | 230000 | N/A | 1982 | $1,966,316,608 | 2,153 | N/A | N/A | 340000000016171 |
| 44 | China Energy Engineering Group Anhui NO.2 Electric Power Construction CO., LTD. | China | Hefei | No. 12600, Fanhua Avenue, Economic Development Zone | Anhui | 230601 | N/A | 1952 | $1,923,623,255 | 2,232 | N/A | N/A | 340000000015154 |
| 45 | Guizhou Wujiang Hydropower Development Co.,ltd. | China | Guiyang | No.9, Xinhua Road, Nanming District | Guizhou | 550002 | N/A | 1992 | $1,915,953,098 | 3,547 | N/A | N/A | 520000000027718 |
| 46 | Marketech International CORP. | Taiwan | Taipei City | 6f, No. 3-2, Yuancyu St. | Taipei City | 115010 | N/A | 1988 | $1,867,883,077 | 773 | N/A | N/A | 23145632 |
| 47 | Toenec CORPORATION | Japan | Nagoya | 1-31-23, Sakae, Naka-ku | Aichi | 460-0008 | N/A | 1944 | $1,817,097,996 | 6,416 | N/A | N/A | 8180001038758 |
| 48 | Broadspectrum Australia (qld) PTY LTD | Australia | Gladstone | 13 Roseanna St | Queensland | 4680 | broadspectrum.***** | 2002 | $1,805,654,928 | 11,210 | N/A | N/A | 100418228 |
| 49 | Beijing Beijing New Energy CO., LTD. | China | Beijing | No.38, Private Technology Park East Road, Qingyundian Town, Daxi | Beijing | 102605 | N/A | 2003 | $1,782,495,000 | 15,000 | N/A | N/A | 110000006108402 |
| 50 | Ameresco, INC. | USA | Framingham | 111 Speen St Ste 410 | Middlesex | 01701 | ameresco.***** | 2000 | $1,769,928,000 | 1,509 | N/A | N/A | 3216839 |