| Haldane Energy Project 3 Limited | London | 2023 |
| Haldane Energy Project 4 Limited | London | 2023 |
| Haldane Energy Project 5 Limited | London | 2023 |
| Haldane Energy Project 6 Limited | London | 2023 |
| Haldane Energy Project 7 Limited | London | 2023 |
| Haldenby Moor Wind Farm Limited | Houghton Le Spring | 2024 |
| Hale Energy Ltd | Neath | 2019 |
| Hale Farm Solar Limited | Kings Langley | 2014 |
| Hale Solar Limited | London | 2014 |
| Halesfield Energy Centre Ltd | Rochford | 2015 |
| Halesworth Energy Storage Limited | Milnthorpe | 2023 |
| Halewood Microgrid Limited | Liverpool | 2020 |
| Halfway Energy Park Limited | London | 2024 |
| Hall Farm Energy Limited | Brackley | 2016 |
| Hall Farm Solar Bess Limited | Cheltenham | 2023 |
| Hall Farm Solar Limited | Kings Langley | 2012 |
| Hall Farm Wind Farm Ltd | Kings Langley | 2009 |
| Hall Hvac Limited | Southampton | 2023 |
| Hall Lane Bess Limited | London | 2024 |
| Hall Solar Ltd | Gatwick | 2011 |
| Halland Renewables Limited | Shepton Mallet | 2025 |
| Hallaughton Grange Solar Bess Limited | Cheltenham | 2023 |
| Hallburn Farm Limited | Kings Langley | 2010 |
| Hallburn Wind Turbines Limited | Wigton | 2015 |
| Hallen Energy Ltd | Stonehouse | 2020 |
| Hallfield Green Energy Limited | Strathaven | 2013 |
| Hallfield Renewables Limited | Peterlee | 2012 |
| Hallmark Energy Limited | Birmingham | 2018 |
| Hallmark Powergen 3 Limited | 1 Oxford Street | 2013 |
| Hallmark Powergen 4 Limited | Burton-On-Trent | 2013 |
| Halo Power Ltd | St. Albans | 2019 |
| Halorus Energy Partners Ltd | London | 2026 |
| Halovia Ltd | London | 2024 |
| Halse Solar Farm Limited | Reading | 2010 |
| Halsnet Capital Limited | London | 2020 |
| Halstead Road Energy Limited | Berkeley | 2023 |
| Halu Ltd | Norwich | 2024 |
| HAM Farm Solar Limited | Cheltenham | 2021 |
| HAM Farm Solar Park Ltd | London | 2014 |
| HAM Western Solar Limited | Liverpool | 2023 |
| Hambleton Electrical Solutions Ltd | Barnstaple | 2023 |
| Hamerton Renewables Limited | Huntingdon | 2012 |
| Hamilton Farms Ltd | West Calder | 2012 |
| Hamilton Hvac Ltd | London | 2010 |
| Hamilton Lane Power Limited | London | 2016 |
| Hamilton Madden Ltd | Saxmundham | 2021 |
| Hamilton March Investments Ltd | Ashford | 2016 |
| Hamilton Solar Ltd | London | 2020 |
| Hammars Hill Energy Limited | Stromness | 2006 |
| Hammars Hill Hydrogen Limited | Roslin | 2024 |
| Hammond's Electrical Ltd | Stevenage | 2020 |
| Hamnaway Ltd | London | 2018 |
| Hampole Windfarm Limited | Bristol | 2012 |
| Hamro Energy Ltd | Hounslow | 2023 |
| Hams Hall EFW Ltd | Stockport | 2022 |
| Hams Hall Green Energy Limited | Faversham | 2021 |
| Hams Hall Holding UK Limited | London | 2025 |
| Hams Hall NG Limited | Cheltenham | 2023 |
| Hams Hall Sustainable Energy Ltd | Birmingham | 2019 |
| Hams Lane NW Bess Limited | Cheltenham | 2023 |
| Hamsard 3767 Limited | London | 2013 |
| Hana (Electric Motion) Limited | Glasgow | 2018 |
| Hannams Generation Hub Limited | Arundel | 2023 |
| Hanningfield Green Limited | London | 2022 |
| Hanover Electrical Services Ltd | Hampton | 2019 |
| Hanover Solar Parks (UK) Ltd | London | 2014 |
| Hanstrom Dienst Ltd | Insch | 2022 |
| Hantech Hvac Services Ltd | Cheadle | 2021 |
| Happy Penguin Home Air Conditioning Limited | Gateshead | 2019 |
| Haque Solar Integrations Ltd | Swansea | 2025 |
| Harborough Commons Energy Reserve Ltd | London | 2025 |
| Harbourne Power Limited | Bristol | 2014 |
| Hardcastle & SON Ltd | Goole | 2015 |
| Harding Electrical Limited | London | 2018 |
| Hardingham Solar Limited | Gatwick | 2013 |
| Hardwick Green Energy Limited | London | 2022 |
| Hare Hill Solar Ltd | London | 2021 |
| Harelaw Generation Limited | Greenock | 2017 |
| Harelaw Holdings Limited | Kirkby Lonsdale | 2016 |
| Hareshaw RIG WF Limited | Motherwell | 2020 |
| Harewood Energy Supply Company Limited | Leeds | 1970 |
| Harker Energy Park Limited | London | 2022 |
| Harkins of Dunmore Ltd | Limavady | 2013 |
| Harlaxton Energy Networks Limited | Grantham | 2010 |
| Harlaxton GAS Networks Ltd | Grantham | 2015 |
| Harlequin Motors Dundee Ltd | Dundee | 2020 |
| Harlesford Solar Farm Limited | London | 2019 |
| Harmony Energy Winds Limited | Cheltenham | 2012 |
| Harp Farm Renewables Limited | Shepton Mallet | 2024 |
| Harper Solar Limited | Reading | 2014 |
| Harperley Lane Solar Park Limited | Shepton Mallet | 2024 |
| Harperrig Wind Ltd | Edinburgh | 2012 |
| Harperstown Power Limited | Co. Antrim | 1994 |
| Harrier Fuels Ltd. | Durham | 1993 |
| Harrison Dimmack Pipelines Ltd | Dudley | 2025 |
| Harrison HOW Limited | London | 1965 |
| Harrison Renewables Ltd | Richmond | 2014 |
| Harrison Wind Ltd | North Shields | 2023 |
| Hartfinder Two Limited | Weybridge | 2022 |
| Hartham Park Community Energy Limited | London | 2012 |