| FAW Side Community Wind Company Ltd | Edinburgh | 2019 |
| Fawley EFW Limited | Manchester | 2014 |
| FB Projects Ltd | Peebles | 2023 |
| FDE Group Ltd | Farnham | 2025 |
| FE Barnard Castle Gridco Ltd | Faversham | 2026 |
| FE Irvine Gridco Limited | Faversham | 2020 |
| FE Irvine Solar Limited | Faversham | 2019 |
| FE Irvine Wind Limited | Faversham | 2019 |
| FE Ware Gridco Ltd | Faversham | 2026 |
| Fearna PSH Limited | Reading | 2023 |
| Fearna Storage Limited | Kendal | 2022 |
| Feckenham Battery Storage Limited | Stonehouse | 2022 |
| Federal Estates Limited | Rushden | 1994 |
| Federal Reserve Limited | Beckenham | 2019 |
| Feeder Grid Storage Limited | Bristol | 2019 |
| Feelcool Solutions Ltd | South Woodham Ferrers | 2024 |
| Feemilano Ltd | Ruislip, | 2025 |
| Feldon Vale Solar Farm Limited | London | 2020 |
| Felindre Hydro Ltd | Llanidloes | 2014 |
| Fell View Solar Limited | Reading | 2014 |
| Fellside Renewable Energy Production Limited | Carnforth | 2013 |
| Feltwell Energy Limited | London | 1999 |
| FEN Ditton Solar and Battery Storage Limited | Cheltenham | 2023 |
| FEN Farm Solar Park Limited | Stroud | 2007 |
| FEN Farm Wind Park Limited | Stroud | 2005 |
| FEN Lane Gridco Limited | Preston | 2022 |
| Fenland Green Energy Ltd | King'S Lynn | 2010 |
| Fenland Renewables Limited | London | 2014 |
| Fenland Windfarms Limited | London | 2004 |
| Fenpower Limited | Bristol | 1999 |
| Fens Sustainable Projects Limited | Sutton | 2020 |
| Fenton Lane Energy Limited | Birmingham | 2017 |
| Fenwick Solar Project Limited | Arundel | 2021 |
| Fenwind Limited | Warboys | 2013 |
| Feorline Burn Ltd | Auchterarder | 2018 |
| Feral Energy Limited | Cardigan | 2015 |
| Fern Brook Solar Farm Limited | London | 2020 |
| Fern Energy Cour Holdings Limited | London | 2014 |
| Fern Energy Holdings Limited | London | 2015 |
| Fernant Micro Hydro Company Limited | Llandrindod Wells | 2013 |
| Ferndale QE Bess 1 Limited | London | 2022 |
| Ferndale Wind Limited | Kings Langley | 2013 |
| Ferneylea 1 Limited | Glasgow | 2011 |
| Fernley Group Ltd | Houghton Le Spring | 2018 |
| Fernley Group NE Ltd | Hartlepool | 2023 |
| Ferring Electrical Services Limited | Worthing | 2017 |
| Ferry Drove Lane Solar Limited | Arundel | 2022 |
| Ferry Farm Community Solar Project C.I.C. | Scorrier | 2015 |
| Ferry Farm Solar Limited | Exeter | 2013 |
| Ferrybridge Hydrogen Limited | Reading | 2023 |
| Fertilis Green Energy Limited | London | 2025 |
| Fes.Uk Limited | Addlestone | 2008 |
| Festrivall Ltd | London | 2026 |
| Fetc Ltd | London | 2024 |
| Fetterangus Power Limited | Peterhead | 2012 |
| Feystown Wind Farm Ltd | Lisburn | 2016 |
| FF Wind Energy Limited | Peterhead | 2020 |
| FFG Energy Centres Ltd | Liverpool | 2021 |
| Fforchdwm Limited | Swansea | 2017 |
| Ffos LAS Solar Developments Limited | Bristol | 2011 |
| Ffridd Uchaf Hydro Ltd | Machynlleth | 2018 |
| Ffrydlan Limited | Machynlleth | 2015 |
| Ffwddog Estate Limited | Stockbridge | 2012 |
| Ffynnon OER Windfarm Limited | London | 1994 |
| FG Services NE Limited | Hartlepool | 2023 |
| FGS Energy Limited | Ashford | 2018 |
| FGS Renewable Ltd | Rochdale | 2025 |
| Fh-Energy Limited | Northampton | 2020 |
| Fhaolain Hydro Ltd | Leeds | 2017 |
| Fialo Utilities Ltd | London | 2020 |
| Fibre 1 Energy Ltd | Elgin | 2018 |
| Fibre Fuel Limited | Reading | 1994 |
| Fibre Power (Slough) Limited | Reading | 1994 |
| Fiddlers Ferry Ltd | London | 2022 |
| Fidelity Energy Limited | London | 2014 |
| Field Beauly Ltd | London | 2023 |
| Field Bicker FEN Ltd | London | 2024 |
| Field Broadford Ltd | London | 2024 |
| Field Corriemoillie Ltd | London | 2023 |
| Field Drum Farm Ltd | Glasgow | 2022 |
| Field Fyrish Ltd | London | 2024 |
| Field Gerrards Cross Ltd | London | 2015 |
| Field Glenniston Ltd | London | 2024 |
| Field Growth Share Ltd | London | 2022 |
| Field Hartmoor Ltd | London | 2022 |
| Field High Marnham Ltd | London | 2025 |
| Field Holmston Ltd | Glasgow | 2022 |
| Field House Renewables Limited | Cambridge | 2021 |
| Field House Solar Limited | London | 2013 |
| Field Kinardochy Ltd | London | 2024 |
| Field Knocknagael Ltd | London | 2023 |
| Field Long Stratton Ltd | London | 2024 |
| Field Netherton Ltd | London | 2025 |
| Field New Deer Ltd | London | 2024 |
| Field Newport Ltd | London | 2021 |
| Field Northburnhill Ltd | London | 2026 |
| Field Oldham Ltd | London | 2017 |
| Field Rigifa Ltd | London | 2024 |
| Field Shurton Ltd | London | 2024 |
| Field Spittal Ltd | London | 2024 |