| Deege Solar | Dartford, United Kingdom | Visit site |
| Deep Wind Offshore | Haugesund, Norway | Visit site |
| Deep Wind Offshore | Concepción, Chile | Visit site |
| Deep Wind Offshore | Tallinn, Estonia | Visit site |
| Deep Wind Offshore | Varberg, Sweden | Visit site |
| Deep Wind Offshore | Seoul, South Korea | Visit site |
| Deepak International | Ludhiana, India | Visit site |
| DefProc Engineering | Liverpool, United Kingdom | Visit site |
| Degerfors Energi AB | Degerfors, Sweden | Visit site |
| Delectrik Systems Private Limited | Gurugram, India | Visit site |
| Deligreen Power | China | Visit site |
| Delixi (Hangzhou) Inverter Co., Ltd. | Hangzhou Shi, China | Visit site |
| Delos Power | Milano, Italy | Visit site |
| Delta Energia | São Paulo, Brazil | Visit site |
| Delta Global Allied Limited | Pune, India | Visit site |
| Delta Green | Praha, Czech Republic | Visit site |
| Delta Networks (Xiamen) Ltd. | People's Republic of China | Visit site |
| Delta Networks (Xiamen) Ltd. | 厦门市, 中国 | Visit site |
| Delta Wye Engineering | Kelowna, Canada | · |
| DeltaCron Renewables | Gloucester, Canada | Visit site |
| Deltalight | Wevelgem, Belgium | Visit site |
| Deltec Energy Solutions | Alberton, South Africa | Visit site |
| Demand Renewables PerformaPV | Osgoode, Canada | · |
| Demuda Solar Energy | Guangzhou Shi, China | Visit site |
| DenAr Ocean Engineering Services SA | Şişli, Türkiye | Visit site |
| Denizüstü Rüzgar Enerjisi Derneği (DÜRED) | Yenimahalle, Türkiye | Visit site |
| Denizüstü Rüzgar Enerjisi Derneği (DÜRED) | Gölbaşı, Türkiye | Visit site |
| Denker Wulf | Sehestedt, Germany | Visit site |
| Dentons Cardenas & Cardenas | Bogotá, Colombia | Visit site |
| Departamento de Engenharia Eletrotécnica e de Computadores da NOVA FCT | Caparica, Portugal | Visit site |
| Department for Energy Security and Net Zero | London, United Kingdom | Visit site |
| Department of Climate Change, Energy, the Environment and Water | Canberra, Australia | Visit site |
| Derun Energy | Canberra, Australia | Visit site |
| Deshmukh Solar Energy Pvt. Ltd. | Nashik, India | Visit site |
| Design Works Engineering | Edmonton, Canada | Visit site |
| DesignTree Service Consultants Pvt Ltd | Bengaluru, India | Visit site |
| Designcore Engineering Ltd. | Calgary, Canada | Visit site |
| Desolenator | Maastricht, Netherlands | Visit site |
| Determination Drilling | Taber, Canada | · |
| Detra Solar | Kaunas, Lithuania | Visit site |
| Deutsche Bank | Frankfurt am Main, Germany | Visit site |
| Deutsche Photovoltaik | Dieburg, Germany | Visit site |
| Deutsche WindGuard | Varel, Germany | Visit site |
| Deutsche Windtechnik | Bremen, Germany | · |
| Deutscher Bauservice GmbH | Cloppenburg, Germany | Visit site |
| Deutsches Pelletinstitut (DEPI) | Berlin, Germany | Visit site |
| Devcon Ecosystems | Zaandam, Netherlands | Visit site |
| Devcon Zonnegilde | Kampen, Netherlands | Visit site |
| Dexler Energy Pvt Ltd | Bengaluru, India | Visit site |
| Deye Service ME | بيروت, Lebanon | Visit site |
| Deye Service ME | Ningbo Shi, China | Visit site |
| Deye Service ME | Lebanon | Visit site |
| Deye Service ME | Malaysia | Visit site |
| Dhabi Contracting L.L.C | Abu Dhabi, United Arab Emirates | Visit site |
| Dhamma Energy | Madrid, Spain | Visit site |
| Di Mario Électricité Sàrl | Carouge, Switzerland | Visit site |
| Diagnostic Photovoltaïque | L'Union, France | Visit site |
| Diamond Renewable Energy | Arnprior, Canada | Visit site |
| Diamond Renewable Energy | Barrie, Canada | Visit site |
| Dieffenbacher Energy | Bludenz, Austria | Visit site |
| Dieffenbacher Energy | Eppingen, Germany | Visit site |
| Differ Community Power | Oslo, Norway | Visit site |
| Dikini | Outremont, Canada | Visit site |
| Dikini | Montréal, Canada | Visit site |
| Dimplex Deutschland | Kulmbach, Germany | Visit site |
| Dina Solar Sverige AB | Linköping, Sweden | Visit site |
| Dinamica Energia Solar | São Carlos, Brazil | Visit site |
| Dipro Conduspar Condutores Elétricos | São José dos Pinhais, Brazil | Visit site |
| Discover Battery | Richmond, Canada | · |
| Dispatch | Amsterdam, Netherlands | Visit site |
| District Heating Solutions | Dranse, Switzerland | Visit site |
| Divea | Sion, Switzerland | Visit site |
| Diverxia | Paterna, Spain | Visit site |
| Diverxia | Alboraia, Spain | Visit site |
| Diverxia | Spain | Visit site |
| Diverxia | USA | Visit site |
| Diverxia | Brazil | Visit site |
| Diverxia | Caribbean | Visit site |
| Diverxia | Italy | Visit site |
| Diverxia | Colombia | Visit site |
| Diverxia | Romania | Visit site |
| Diverxia | United Kingdom | Visit site |
| Diwakar Solar | Jaipur, India | Visit site |
| Doart Energy | Islamabad, Pakistan | Visit site |
| Docan ENERGY | Northwich, United Kingdom | Visit site |
| Doha Petroleum Construction Co. W.L.L | Doha, Qatar | Visit site |
| Dome International for Environmental and Engineering Services | مَسْقَط, Oman | Visit site |
| Domolynx | Saint-Laurent, Canada | Visit site |
| Doncaster Cables | Doncaster, United Kingdom | Visit site |
| Done | Stockholm, Sweden | Visit site |
| Dong Fang Offshore 東方風能 (DFO) | 臺中市, Taiwan | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Dongwan Shi, China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Jiaxing Shi, China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Huizhou, China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Dongguan, China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Jiaxing, China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Malaysia | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Hong Kong, China | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | India | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | Thailand | Visit site |
| Dongguan Pengjin Machinery Technology Co.,Ltd. | South Korea | Visit site |
| Dongguan Yuanze ELectric Co.,Ltd | Dongwan Shi, China | Visit site |
| Dongguan Yuanze ELectric Co.,Ltd | Dongguan, China | Visit site |
| Dongjiaxin | Shenzhen Shi, China | Visit site |
| Donnergy | China | Visit site |
| Doosan Enerbility | Changwon-si, South Korea | Visit site |
| Doosan Lentjes | Ratingen, Germany | Visit site |
| Doosan Lentjes | Praha, Czech Republic | Visit site |
| Doral | Ramat Gan, Israel | Visit site |
| Dornier Group | Berlin, Germany | Visit site |
| Dornier Hinneburg GmbH | Willstätt, Germany | Visit site |
| Dotz Nano Ltd. | Kfar Sava, Israel | Visit site |
| Doğuhan Enerji | Ataşehir, Türkiye | Visit site |
| Dr. Spang Ingenieurgesellschaft | Witten, Germany | Visit site |
| Dragados Canada, Inc. | Toronto, Canada | Visit site |
| Drakes Renewables | Harpenden, United Kingdom | Visit site |
| Dravske elektrarne Maribor | Maribor, Slovenia | Visit site |
| Drax Group UK | United Kingdom | Visit site |
| Dredge Masters Ghana Limited | Accra, Ghana | Visit site |
| Dreev | Saint-Louis, France | Visit site |
| Drishti Foundation Trust | Ahmedabad, India | Visit site |
| Driven by Values, now Stantec | Sittard, Netherlands | · |
| DualSun | Marseille, France | Visit site |
| Dualsol | Madrid, Spain | Visit site |
| Ducab | Dubai, United Arab Emirates | Visit site |
| Dunia | Berlin, Germany | Visit site |
| Duranet verduurzaamt | Haarlem, Netherlands | Visit site |
| Durapower Holdings Pte Ltd | Ghana | · |
| Durasol Energi | Gurugram, India | Visit site |
| Durasolar BV | Didam, Netherlands | Visit site |
| Duratron | Dubai, United Arab Emirates | Visit site |
| Dutch Solar Energy | Tilburg, Netherlands | Visit site |
| Dutch Wave Power | Netherlands | Visit site |
| Duurzaam Opgewekt | Geldermalsen, Netherlands | Visit site |
| DyMac | Newcastle, Ireland | · |
| Dynamic Corporate Solutions Pvt ltd | India | Visit site |
| Dynamic Power | فريج العسيري, Qatar | Visit site |
| Dynavolt Tech | Shantou Shi, China | · |
| Dynelectro | København, Denmark | · |
| Dynergy Energy Management | Vaughan, Canada | Visit site |
| Dyness | Suzhou Shi, China | Visit site |
| Dyness | 潮州鎮, Taiwan | Visit site |
| Dyness | Xi'an Shi, China | Visit site |
| Dyness | Taizhou Shi, China | Visit site |
| Dyness | Shenzhen Shi, China | Visit site |
| Dyness | Singapore, Singapore | Visit site |
| Dyness | Suzhou, China | Visit site |
| Dyness | Xi'an, China | Visit site |
| Dyness | Taizhou, China | Visit site |