| Association of Consulting Engineering Companies BC (ACEC-BC) | Vancouver, Canada | Visit site |
| Association on Energy Efficiency and Energy Saving in Ukraine | Kyiv, Ukraine | Visit site |
| Associazione Italiana Riscaldamento Urbano - AIRU | Milano, Italy | Visit site |
| Associação Brasileira de Energia Solar Fotovoltaica - ABSOLAR | São Paulo, Brazil | Visit site |
| Aster e Technologies | Bengaluru, India | Visit site |
| Astera Solar | Sandnes, Norway | Visit site |
| Astera Solar | Klepp Stasjon, Norway | Visit site |
| Asterion Energies | Madrid, Spain | Visit site |
| Astra Green Solutions | Australia | Visit site |
| Astra Racking | Kirkton, Canada | Visit site |
| Astra Solar | Belo Horizonte, Brazil | Visit site |
| Astral Systems | Bristol, United Kingdom | Visit site |
| Astrea Energia | Milano, Italy | · |
| AstroEnergy | Gorzów Wielkopolski, Poland | · |
| Asun Solar Power (P) Ltd. | New Delhi, India | Visit site |
| Asun Trackers Pvt Ltd. | New Delhi, India | · |
| Asunim Türkiye | Çankaya, Türkiye | · |
| Atalay Grup Enerji A.Ş. | Çankaya, Türkiye | Visit site |
| Atama Solar Energy BV | Elst, Netherlands | Visit site |
| Atama Solar Energy BV | Heteren, Netherlands | Visit site |
| Atama Solar Energy BV | Genk, Belgium | Visit site |
| Atenco | 三重區, Taiwan | Visit site |
| Ateş Wind Power | Bergama, Türkiye | Visit site |
| Athon | São Paulo, Brazil | Visit site |
| Atkins | Epsom, United Kingdom | · |
| AtkinsRéalis | Montréal, Canada | Visit site |
| Atlansun | Nantes, France | Visit site |
| Atlantic Green | London, United Kingdom | Visit site |
| Atlantic Hydrogen Alliance | Halifax, Canada | Visit site |
| Atlantic Renewables | Altrincham, United Kingdom | · |
| Atlantica Sustainable Infrastructure Ltd | London, United Kingdom | Visit site |
| Atlantis Geoservices Ltd | Norwich, United Kingdom | Visit site |
| Atlantium Technologies | Indonesia | Visit site |
| Atlas Power Technologies Inc. | Abbotsford, Canada | Visit site |
| Atlas Renewables | Sydney, Australia | Visit site |
| Atmoce | Amsterdam, Netherlands | Visit site |
| Atmos Consulting Ltd | Edinburgh, United Kingdom | Visit site |
| Atmos Consulting Ltd | Dingwall, United Kingdom | Visit site |
| Atmos Consulting Ltd | Mold, United Kingdom | Visit site |
| Atmosfera | Kyiv, Ukraine | · |
| Atmosfuture Limited | London, United Kingdom | Visit site |
| Atom bv | Melle, Belgium | Visit site |
| Atom-ESS | Dursley, United Kingdom | · |
| Aton Enerji | Konak, Türkiye | Visit site |
| Atr Grup | Konak, Türkiye | Visit site |
| Atrae Energía | València, Spain | · |
| Atrato Onsite Energy | London, United Kingdom | Visit site |
| Attero | Liège, Belgium | Visit site |
| Attexo Group | Brisbane, Australia | Visit site |
| Atılgan Solar Enerji ve Mühendislik Hizmetleri Ltd. Şti. | Muratpaşa, Türkiye | Visit site |
| AuRA Digital Solaire | Lyon, France | · |
| Audace Technologies inc. | Rimouski, Canada | · |
| Audax Renovables | Badalona, Spain | · |
| August Energy | Singapore, Singapore | Visit site |
| Augusta & Co | London, United Kingdom | Visit site |
| Augusta Abogados | Barcelona, Spain | Visit site |
| Augwind Energy | Yaqum, Israel | · |
| Aukera Energy | Brussels, Belgium | Visit site |
| Aunilec | Ludwigshafen am Rhein, Germany | Visit site |
| Aurasolar.com | Madrid, Spain | Visit site |
| Aurecon | Melbourne, Australia | · |
| Auren Energia | São Paulo, Brazil | Visit site |
| Aureos | London, United Kingdom | Visit site |
| Auris Energia | Kotka, Finland | Visit site |
| Aurora Wind Power | Johannesburg, South Africa | · |
| AusPac Solar | Brisbane, Australia | Visit site |
| Ausecology | Brisbane, Australia | Visit site |
| Auspro Group Pty Ltd | Melbourne, Australia | Visit site |
| Austra Energy | Sydney, Australia | Visit site |
| Australia Wide Solar | Sydney, Australia | Visit site |
| Australian Premium Solar (India) Ltd. | Ahmedabad, India | Visit site |
| Australian Renewable Energy Agency (ARENA) | Canberra, Australia | Visit site |
| Australian Solar Designs | South West Rocks, Australia | Visit site |
| Austria Solar | Vienna, Austria | Visit site |
| Autarco | Eindhoven, Netherlands | Visit site |
| Autarq GmbH | Prenzlau, Germany | Visit site |
| Autarsys | Berlin, Germany | Visit site |
| Auto Energy | Campinas, Brazil | · |
| Autonics Automation India Pvt. Ltd. | Navi Mumbai, India | Visit site |
| Autonometrics | Perth, Australia | Visit site |
| Autovert Technologies Pvt Ltd | Bengaluru, India | Visit site |
| Auttom | Caxias do Sul, Brazil | Visit site |
| Aux Solar | Ningbo Shi, China | Visit site |
| Avaada Electro Pvt Ltd | Mumbai, India | Visit site |
| Avaada Electro Pvt Ltd | Dadri, India | Visit site |
| Avaada Electro Pvt Ltd | Nagpur, India | Visit site |
| Avaada Electro Pvt Ltd | Dadri GB Nagar, India | Visit site |
| Avaada Group | Mumbai, India | Visit site |
| Availon United Wind Service | Rheine, Germany | Visit site |
| Availon United Wind Service | Aarhus, Denmark | Visit site |
| Avalon Mechanical | Esquimalt, Canada | Visit site |
| Avanti Wind Systems | Stockholm, Sweden | Visit site |
| Avasco Solar | Ieper, Belgium | Visit site |
| Avendus | Mumbai, India | Visit site |
| Avesta Battery & Energy Engineering MK (ABEE MK) | Skopje, North Macedonia | Visit site |
| Avfall Sverige | Malmö, Sweden | Visit site |
| Avg Innovation-Connettiamo il mondo al sole attraverso soluzioni nel settore dell'energia solare | Rimini, Italy | Visit site |
| Avils Consulting Ltd | Bath, United Kingdom | Visit site |
| Avishakti Solar | Mumbai, India | Visit site |
| AxSun Solar GmbH & Co. KG | Laupheim, Germany | Visit site |
| Axess Power | Doha, Qatar | Visit site |
| Axi | Hull, United Kingdom | Visit site |
| Axial Solar | Manuel, Spain | Visit site |
| Axis Energy Group | Hyderabad, India | Visit site |
| Axis Power | Kottayam, India | Visit site |
| Axis Renováveis | São Paulo, Brazil | Visit site |
| Axon' Cable | Fromentières, France | Visit site |
| Axtora Energy - Energy Cost Optimization, Waste Heat Conversion to Electrical Energy | Eberswalde, Germany | Visit site |
| Aydem Yenilenebilir Enerji | Merkezefendi, Türkiye | Visit site |
| Ayesa | Sevilla, Spain | Visit site |
| Ayming | Levallois-Perret, France | Visit site |
| Ayond | Blomsterdalen, Norway | Visit site |
| Ayrton Energy | Calgary, Canada | Visit site |
| Azelio | Göteborg, Sweden | Visit site |
| Azets Consulting | Bergen, Norway | Visit site |
| Azimut Solar Enerji Sistemleri A.Ş. | Karşıyaka, Türkiye | Visit site |
| Aztech Solar | Beresfield, Australia | Visit site |
| Azteq Energy | Antwerpen, Belgium | Visit site |
| Azure Power | Gurugram, India | Visit site |
| B & A Energy Oy | Tampere, Finland | · |
| B Current Impact Investment Inc. | 臺北市, Taiwan | Visit site |
| B&K Management Consulting | Tel Aviv-Yafo, Israel | Visit site |
| B+E Solutions GmbH | Achim, Germany | Visit site |
| B-InRoof | Wetzikon, Switzerland | Visit site |
| B.F. AUTOMATION S.R.L. | Belfiore, Italy | Visit site |
| B.F. AUTOMATION S.R.L. | Caldiero, Italy | Visit site |
| BAI | London, United Kingdom | · |
| BAJ Solar | Suzhou Shi, China | Visit site |
| BALTI SOLAR | Kortrijk, Belgium | Visit site |
| BAM BAM Pile Driving | South West Rocks, Australia | Visit site |
| BAM UK & Ireland | London, United Kingdom | Visit site |
| BATKON Battery Control Technologies Inc. | Sarıyer, Türkiye | Visit site |
| BATKON Battery Control Technologies Inc. | Istanbul, Türkiye | Visit site |
| BATTLINK | Guangzhou Shi, China | Visit site |
| BATx | Medellín, Colombia | Visit site |
| BAUER Elektroanlagen | Buchbach, Germany | Visit site |
| BAUER Solar GmbH | Selzen, Germany | · |
| BBS Automation | Garching bei München, Germany | Visit site |
| BCHAR | Zürich, Switzerland | Visit site |
| BDHM Consultants PVT. LTD. | Balasinor, India | Visit site |
| BDHM Consultants PVT. LTD. | India | Visit site |
| BDSE électricité | Voreppe, France | Visit site |
| BECIS - Energy as a Service | Singapore, Singapore | Visit site |
| BEEM | Patna, India | Visit site |
| BELECTRIC España | Murcia, Spain | · |
| BELECTRIC GmbH | Kolitzheim, Germany | · |
| BELECTRIC UK | Chippenham, United Kingdom | · |
| BERMAD | Hungerford, United Kingdom | Visit site |
| BFP Enerji A.S. | Beşiktaş, Türkiye | Visit site |
| BFP Service | Modugno, Italy | Visit site |