| Gsii Bent Spur Solar Farm Limited | Exeter | 2016 |
| Gsii Bentley Estate Limited | London | 2014 |
| Gsii Bicester Solar Farm Limited | Hove | 2012 |
| Gsii Bolsovermoor Quarry Limited | London | 2012 |
| Gsii Carmarthen Solar Limited | Hove | 2014 |
| Gsii Chafarm CFD Limited | London | 2013 |
| Gsii Clay Cross Limited | Hove | 2015 |
| Gsii Cwrt Henllys Limited | London | 2013 |
| Gsii Defford Solar Limited | London | 2016 |
| Gsii Dorset Solar Farm Limited | Exeter | 2014 |
| Gsii Errol Solar PV Limited | London | 2014 |
| Gsii Fields Farm Limited | London | 2011 |
| Gsii Firs Road 1 C.I.C. | London | 2015 |
| Gsii Firs Road 2 C.I.C. | London | 2015 |
| Gsii Gelli Gron Limited | London | 2014 |
| Gsii Gorse Lane Solar Limited | London | 2017 |
| Gsii Hafod Limited | London | 2013 |
| Gsii Hafod Solar C.I.C. | London | 2015 |
| Gsii Hill Hall Limited | London | 2011 |
| Gsii Homestead Solar Farm Limited | Hove | 2013 |
| Gsii Hornacott Limited | London | 2014 |
| Gsii Laceby 1 C.I.C. | London | 2015 |
| Gsii Laceby 2 C.I.C. | London | 2015 |
| Gsii Llancadle Solar Farm Limited | London | 2014 |
| Gsii Long Meadow Farm Limited | London | 2014 |
| Gsii Lower Farm Binsted Limited | London | 2013 |
| Gsii Meadow Farm Limited | London | 2014 |
| Gsii Middle Balbeggie Limited | London | 2014 |
| Gsii Millar Farm Limited | London | 2014 |
| Gsii Morfa Limited | London | 2012 |
| Gsii Mount Farm Limited | Hove | 2013 |
| Gsii Netley Solar Limited | London | 2014 |
| Gsii NI Solar Cluster Limited | London | 2012 |
| Gsii Northmoor Substation Limited | London | 2013 |
| Gsii Park Farm West Limited | London | 2014 |
| Gsii Parsonage Wood Limited | London | 2013 |
| Gsii PEN Rhiw Limited | London | 2012 |
| Gsii Potters Bar Limited | Hove | 2015 |
| Gsii Rose & Crown Limited | Hove | 2013 |
| Gsii Safeguard Bradwall Limited | London | 2014 |
| Gsii Sea View Limited | London | 2015 |
| Gsii Sharland Farm Limited | London | 2014 |
| Gsii South Creake Limited | London | 2013 |
| Gsii Stragglethorpe Limited | London | 2013 |
| Gsii Streetfield Solar Limited | London | 2013 |
| Gsii Teyrdan 1 C.I.C. | London | 2015 |
| Gsii Teyrdan Solar Limited | London | 2013 |
| Gsii Thorne Solar Limited | London | 2015 |
| Gsii Thornham Solar Limited | London | 2013 |
| Gsii Trefullock Solar Limited | London | 2010 |
| Gsii Upper Meadowley Limited | Hove | 2014 |
| Gsii Vine Farm Limited | Hove | 2014 |
| Gsii Wick Road Solar PV Limited | London | 2014 |
| GSL Commissioning Ltd | Bishop'S Stortford | 2019 |
| GSS Contracts Ltd | Glasgow | 2014 |
| GSW Group Ltd | Meopham | 2021 |
| GT R4 Limited | London | 2021 |
| GT Renewables Ltd | Newbiggin-By-The-Sea | 2022 |
| GTG Biogas (Ballymoyle) Limited | Cookstown | 2011 |
| GTG Biogas (Toomebridge) Limited | Coleraine | 2011 |
| GTH Technical Services Limited | Crewe | 2008 |
| GTM Lighting Limited | Hampton Hill | 2010 |
| GU1 Grid Limited | Motherwell | 2024 |
| GU2 Grid Limited | Motherwell | 2024 |
| Guangzhou Luckon Technology Co., Ltd | West Midlands, England | 2024 |
| Guardian Energy Holdings Limited | Ipswich | 2003 |
| Guardian Energy Limited | Needham Market | 2003 |
| Guardian Maintenance Limited | Milton Keynes | 2009 |
| Guardian Solar Ltd | London | 2010 |
| Guinness Sustainable Infrastructure Limited | Norwich | 2015 |
| Guinness Sustainable Schools 2 Ltd | Norwich | 2014 |
| Guinness Sustainable Schools Ltd | Norwich | 2013 |
| Guisborough Solar Limited | London | 2013 |
| Gulliver Limited | Norwich | 2002 |
| Gumala Bess Limited | Bristol | 2021 |
| Gunfleet Sands II Limited | London | 2007 |
| Gunfleet Sands Limited | London | 2000 |
| Gunheath Turbine Limited | Wadebridge | 2015 |
| Gunhill Energy Limited | Inverurie | 2014 |
| Gunning and Mcguckin Utilities Limited | Maghera | 2020 |
| Gunvor UK Limited | London | 2018 |
| Gusto Wind Limited | Belfast | 2014 |
| Guston C Solar Farm Limited | Hove | 2013 |
| GUY Energy Ltd | St Ives | 2019 |
| Guymers Ltd | Portsmouth | 2025 |
| GV Energy Ltd | London | 2026 |
| GV Renewable Ltd | London | 2025 |
| Gvac Ltd | Glasgow | 2006 |
| GVO Biomass Limited | London | 2014 |
| GVO Wind NO. 1 Ltd | London | 2011 |
| GVO Wind NO. 10 Limited | London | 2013 |
| GVO Wind NO. 11 Limited | London | 2013 |
| GVO Wind NO. 12 Limited | Edinburgh | 2011 |
| GVO Wind NO. 13 Limited | London | 2013 |
| GVO Wind NO. 14 Limited | London | 2013 |
| GVO Wind NO. 16 Limited | London | 2013 |
| GVO Wind NO. 20 Limited | London | 2014 |
| GVO Wind NO. 21 Limited | London | 2014 |
| GVO Wind NO. 22 Limited | London | 2014 |
| GVO Wind NO. 23 Limited | London | 2014 |