| R-energy | Eindhoven, North Brabant | Visit site |
| RANA ENERGY CO. | Tehran, Tehran | Visit site |
| RASLAG Corp. | Pasig, Pasig | Visit site |
| RAW Energy | Kuala Lumpur, Kuala Lumpur | Visit site |
| RAW Solid Fuels | Kuala Lumpur, Kuala Lumpur | Visit site |
| RAYZON SOLAR PVT. LTD. | Junagadh, Gujarat | Visit site |
| RBS Solar | Toluca Lake, California | Visit site |
| RCD | Barcelona, Barcelona | Visit site |
| RCL Mechanical | Raynham, Massachusetts | Visit site |
| RCM | Pennsauken, New Jersey | Visit site |
| RCT Power | Konstanz, Baden-Württemberg | Visit site |
| RCT Solutions GmbH | Konstanz, Baden-Württemberg | Visit site |
| RDS Solar | Dallas, Texas | Visit site |
| RE Royalties | Vancouver, British Columbia | Visit site |
| RE Technologies GmbH | Hamburg, Hamburg | Visit site |
| RE+ Central | Alexandria, VA | Visit site |
| RE:GEN Group | Sunderland, England | Visit site |
| REA GLOBAL | Redland Bay, Queensland | Visit site |
| REAL ALPHA | Roma, Rome | Visit site |
| REALI | Lima, Lima Province | Visit site |
| REAR®(Renewable Energy Association of Rajasthan) - Industry Body - Solar Association - NGO | Kolayat, Rajasthan | Visit site |
| REBI | San Sebastián de los Reyes, Madrid | Visit site |
| REC Group | Staré Město, Zlín | Visit site |
| RED Engineering Design | London, England | Visit site |
| REDEN | Saint-Julien-de-Concelles, Loire-Atlantique | Visit site |
| REECO Group | Reutlingen, Baden-Württemberg | Visit site |
| REGGIO | Santiago, Santiago Metropolitan Region | Visit site |
| REMBE | Fort Mill, South Carolina | Visit site |
| REMONDIS Gruppe | Lünen, North Rhine-Westphalia | Visit site |
| REMONDIS Production GmbH | Lünen, North Rhine-Westphalia | Visit site |
| REMONDIS Sverige | Hisings Backa, Västra Götaland | Visit site |
| RENAISSANCE CAPITAL d.o.o. | Zagreb, Zagreb | Visit site |
| RENQ Power Solutions India Pvt Ltd | Pala, Kerala | Visit site |
| RENTALOAD | Gleizé, Rhône | Visit site |
| REON Technology | Somerville, Massachusetts | Visit site |
| REPP (Renewable Energy Performance Platform) | London, England | Visit site |
| RESA Power | Houston, Texas | Visit site |
| REVCOO | Vénissieux, Rhône | Visit site |
| REX Electric & Technologies, LLC | Chicago, Illinois | Visit site |
| REenergizeCO | Fountain, Colorado | Visit site |
| REpowering Schools | Harrisonburg, VA | Visit site |
| RFC Ambrian | Sydney, New South Wales | Visit site |
| RGS Energy | Denver, Colorado | Visit site |
| RHI Magnesita | Vienna, Vienna | Visit site |
| RICH SOLAR | Norco, California | Visit site |
| RINA | Genova, Genoa | Visit site |
| RITEWAYS | Bengaluru, Karnataka | Visit site |
| RLC Engineering | Augusta, Maine | Visit site |
| RM Surveys | Perth, Western Australia | Visit site |
| RMB Hydroseeding | Dursley, England | Visit site |
| RMS Energy Co, LLC | Little Falls, Minnesota | Visit site |
| ROEF | Son en Breugel, North Brabant | Visit site |
| ROHM Semiconductor Europe | Willich, North Rhine-Westphalia | Visit site |
| ROSI | Grenoble, Isère | Visit site |
| ROTORWORKS GmbH | Berlin, Berlin | Visit site |
| RP Global | Vienna, Vienna | Visit site |
| RP Solar | Chennai, Tamil Nadu | Visit site |
| RPS Switchgear SA (Switchgear & Electrical Engineering Services) | Boksburg, Gauteng | Visit site |
| RPT | Houston, Texas | Visit site |
| RRE Inc Electrical Contractor | Pleasant Grove, California | Visit site |
| RRPT Hydro | Washington, District of Columbia | Visit site |
| RS WINDTECH ENGINEERS (P) LTD | Thovala, Tamil Nadu | Visit site |
| RS Windtech Engineers Private Limited | Thovala, Tamil Nadu | Visit site |
| RSF Capital Partners LLP | London, England | Visit site |
| RSK Group | Frodsham, England | Visit site |
| RSM Spain | Barcelona, Barcelona | Visit site |
| RUDRA SOLAR ENERGY | Ahmedabad, Gujarat | Visit site |
| RUNHOOD POWER INC. | Walnut, CA | Visit site |
| Rabot Dutilleul Construction | Hauts-de-France | Visit site |
| Radial Torque Tools B.V. | Soest, Utrecht | Visit site |
| Radian Generation | Charlotte, North Carolina | Visit site |
| Radiocrafts | Oslo, Oslo | Visit site |
| Raijin Solar Energy LLP | Ahmedabad, Gujarat | Visit site |
| Rainbow Steel | Tianjin, Tianjin | Visit site |
| Raise Green | Pittsburgh, Pennsylvania | Visit site |
| Raiseking Lighting | Guangzhou Shi, Guangdong | Visit site |
| Raj Petro - A Brenntag Group Company | Chennai, Tamil Nadu | Visit site |
| Ramboll | København, Capital Region of Denmark | Visit site |
| Ramery | Erquinghem-Lys, Nord | Visit site |
| Ramesh Corp. | Tripureswor, Bagmati Province | Visit site |
| Ramón y Cajal Abogados | Madrid, Madrid | Visit site |
| Rana Energy (Techstars ‘23) | London, England | · |
| Rank® – Organic Rankine Cycle (ORC) and High-Temperature Heat Pumps (HTHP) | La Vall d'Uixó, Castellón | Visit site |
| Rapidan Energy Group | Washington, District of Columbia | Visit site |
| Raptor Maps | Somerville, Massachusetts | Visit site |
| Ravano Power | Cogoleto, Genoa | Visit site |
| RavenVolt Inc, An ABM Company | Cumming, Georgia | Visit site |
| Rawabi Holding Group | Fort Payne, Alabama | Visit site |
| RayFlex | · | Visit site |
| Raycap | Post Falls, Idaho | Visit site |
| Raydean Industries | Jaipur, Rajasthan | Visit site |
| Rayleigh Solar Tech | Dartmouth, Nova Scotia | Visit site |
| Raymetrics S.A. | Amarousio, Attica | Visit site |
| Raymond Solar | Årsta, Stockholm | Visit site |
| Rayshely Power | Zhejiang | Visit site |
| Rayva | Nogales, Arizona | Visit site |
| Re Sustainability Limited | Hyderabad, Telangana | Visit site |
| ReNew | Gurugram, Haryana | Visit site |
| Real Ventures | Montréal, Quebec | Visit site |
| Realeen Solar (Laos) Co.,Ltd | · | Visit site |
| Reap Battery USA | Tuzla, Istanbul | Visit site |
| Rechargion Energy | Pune, Maharashtra | Visit site |
| Recontek | Riga, Riga | Visit site |
| Recoolit | · | Visit site |
| RectorSeal | Houston, Texas | Visit site |
| Red Top Electric | Livermore, California | Visit site |
| Redaptive | Denver, Colorado | Visit site |
| Redarc Electronics | Adelaide, South Australia | Visit site |
| Redeux Energy | Denver, Colorado | Visit site |
| Redo Biosolutions | Porsgrunn, Telemark | Visit site |
| RedoxNRG | Narva, Ida-Viru | Visit site |
| Redwood Electric Group | Santa Clara, California | Visit site |
| Redwood Materials | Carson City, Nevada | Visit site |
| Reefy | Delft, South Holland | Visit site |
| Reenergy Battery & Solar | Santa Cruz, California | Visit site |
| Regascold | Aachen, North Rhine-Westphalia | Visit site |
| Regatron - Programmable Power Supplies | Rorschach, St. Gallen | Visit site |
| Regen Power Pty Ltd | Perth, Western Australia | Visit site |
| RegenX | Melbourne, Victoria | Visit site |
| Regiolux International | Königsberg in Bayern, Bavaria | Visit site |
| Regiolux Nederland B.V. | Woerden, Utrecht | Visit site |
| Reiling Group | Harsewinkel, North Rhine-Westphalia | Visit site |
| Reinhard Haustechnik AG | Sarnen, Obwalden | Visit site |
| Rekart Innovations Private Limited | Gurugram, Haryana | Visit site |
| Reliance Energy | Lahore, Punjab | Visit site |
| Reliance Industries Limited | Navi Mumbai, Maharashtra | Visit site |
| Reliance Piles Inc | New York, New York | Visit site |
| Reliance Power Limited | · | Visit site |
| Reliance Renewable Energy Pvt Ltd | Kathmandu, Bagmati Province | Visit site |
| Relode | London, England | Visit site |
| Rely | Brussels, Brussels-Capital | Visit site |
| RelyEZ Energy Storage | Shenzhen Shi, Guangdong | Visit site |
| Relyion Energy Inc | Hayward, California | Visit site |
| Rematter | Zug, Zug | Visit site |
| Remedium | Cambridge, England | Visit site |
| Remee Wire & Cable | Florida, New York | Visit site |
| Remora Technology | Gebze, Kocaeli | Visit site |
| Remove and Replace Solar | Aurora, Colorado | Visit site |
| Renaissance Fusion | Saint-Priest, Rhône | Visit site |
| Renasci Oostende | Oostende, West Flanders | Visit site |
| Renco | Pesaro, Pesaro and Urbino | Visit site |
| Renerix Solar | Ciudad Real, Ciudad Real | Visit site |
| Renesas Electronics | 東京都, Tokyo Prefecture | Visit site |
| Renesource Inc. | Manila, Manila | Visit site |
| Renevolt | Ål, Buskerud | Visit site |
| Renew Home | Oakland, California | Visit site |
| Renewable Advisors | New York, New York | Visit site |
| Renewable America | San Jose, California | Visit site |
| Renewable Concepts LLC | Neodesha, Kansas | Visit site |
| Renewable Energy Services of New England | Cranston, Rhode Island | Visit site |