| Bluestone Mitchell Farms 1 Ltd | Canvey Island | 2021 |
| Bluestone Mount Pleasant Ltd | Canvey Island | 2025 |
| Bluestone Ponthir 1 Ltd | Canvey Island | 2020 |
| Bluestone Rettendon 1 Ltd | Canvey Island | 2020 |
| Bluestone Rhadyr 1 Ltd | Canvey Island | 2020 |
| Bluestone Rushcliffe Ltd | Canvey Island | 2022 |
| Bluestone SEC 1 Ltd | Canvey Island | 2024 |
| Bluestone ST Peters Lane 2 Ltd | Canvey Island | 2022 |
| Bluestone Stalham 1 Ltd | Canvey Island | 2021 |
| Bluestone Stanely 1 Ltd | Canvey Island | 2024 |
| Bluestone Summerston 1 Ltd | Canvey Island | 2024 |
| Bluestone Sunnydale Farm 1 Ltd | Canvey Island | 2022 |
| Bluestone Trebugal 1 Ltd | Canvey Island | 2021 |
| Bluestone Upminister 2 Ltd | Canvey Island | 2024 |
| Bluestone Upminster Ltd | Canvey Island | 2022 |
| Bluestone Woolshots Ltd | Canvey Island | 2025 |
| Bluestream Trading Co Limited | Norwich | 2015 |
| Bluetec GAS Ltd | London | 2018 |
| Bluwood Air Conditioning Limited | Walsall. | 2025 |
| Blyth Energy Limited | Worksop | 2024 |
| Blyth Offshore Demonstrator Limited | Houghton Le Spring, Sunderland | 2014 |
| Blyth Solar Farm Limited | London | 2021 |
| Blyth-Hamilton Limited | Dunfermline | 2018 |
| Blythe House Solar Farm Limited | Birmingham | 2020 |
| Bmcwind Ltd | Barrow-In-Furness | 2025 |
| BME Ltd | Downpatrick | 2016 |
| BMK (N.I.) Ltd | Larne | 2023 |
| BMS Commissions Limited | Basildon | 2006 |
| BNM Technology Group Ltd | Halifax | 2022 |
| BNP Bioenergy Ltd | London | 2019 |
| Bnrg Gorse PLC | London | 2013 |
| Bnrg HOO Solar PLC | London | 2012 |
| Bnrg IOW Limited | London | 2012 |
| Bnrg Langmead Limited | Bosham | 2014 |
| BNX Energy Ltd | Huddersfield | 2021 |
| Boardinghouse Windfarm Limited | Bristol | 2011 |
| Boat of Garten Bess Limited | London | 2021 |
| Bobbing Solar Limited | London | 2013 |
| Bobby Ross (Hydro) Limited | Acharacle | 2018 |
| Bockingfold Solar Limited | London | 2021 |
| Bodellick Enterprises Limited | Wadebridge | 2013 |
| Bodica Limited | London | 2012 |
| Bodinglee Wind Farm Limited | Houghton-Le-Spring | 2020 |
| Bodmin Solar Limited | Bristol | 2011 |
| Bodrach Generation Ltd | Bridgend | 2013 |
| Bodrhyddan Farming Company Limited(The) | Clwyd | 1956 |
| Bodvel Power Limited | Malton | 2016 |
| Bodwen Solar Project Limited | Hove | 2013 |
| BOE Energy Co Limited | Blairgowrie | 2016 |
| Boers Energy Limited | Evesham | 2016 |
| Boganlea Renewable Energy Limited | Exeter | 2006 |
| Bogfechel Energy Limited | Aberdeen | 2010 |
| Boghead 2 WT Limited | Glasgow | 2014 |
| Boghead WT Limited | Edinburgh | 2014 |
| Boiler AID Ltd | Aylesford | 2021 |
| BOL Energy Limited | Hull | 2025 |
| Bolam Energy Limited | London | 1999 |
| Boldcraft Limited | Bromsgrove | 1991 |
| Boli Innovation Limited | London | 2023 |
| Bolney Green Energy Hub 1 Limited | London | 2019 |
| Bolney Green Energy Hub 2 Limited | London | 2019 |
| Bolney Green Energy Hub 3 Limited | London | 2019 |
| Bolney Green Energy Hub 4 Limited | Tunbridge Wells | 2022 |
| Bolney Green Limited | London | 2020 |
| Bolshan Renewables Limited | Edinburgh | 2015 |
| Bolttas Energy Europe Ltd | Coventry | 2022 |
| Boltvaultuk Ltd | Benfleet | 2024 |
| Boma Energy Limited | Dunblane | 2014 |
| Bona Solar Ltd | London | 2014 |
| Bonerbo Renewable Energy Limited | Aberdeen | 2013 |
| Bonnie Insualtion Ltd | Barrow-Upon-Humber | 2025 |
| Bonnyknox Solar Limited | Kings Langley | 2025 |
| Bonnyton Energy Ltd | Heriot | 2012 |
| Boom Bacup Storage Limited | Arundel | 2018 |
| Boomerang Energy Limited | London | 2017 |
| Boor Hydro Limited | Chester | 2009 |
| Boost Managed Services Ltd | Rainham | 2026 |
| Boothby Solar Limited | Hove | 2013 |
| Boothman Farm Limited | St, John'S Wood | 2024 |
| Border Heating Services Ltd | Essex | 2018 |
| Bordessa Cooling Services Ltd | Chesham | 2022 |
| Borealis Energy Limited | Helensburgh | 2013 |
| Boreas Energy Limited | London | 2015 |
| Boreland Energy Ltd | Killin | 2022 |
| Bores Investment Limited | Walton-On-Thames | 2026 |
| Borough Wind Limited | Co. Fermanagh | 2014 |
| BOS Electrical Services Limited | Hemel Hempstead | 2007 |
| Bos-Uie Limited | Cardiff | 1972 |
| Boskennal Limited | Norwich | 2013 |
| Boston Heat & Power Ltd | St. Albans | 2022 |
| Boston RE Ltd | Manchester | 2013 |
| Boston Solar Limited | London | 2015 |
| Botley Green Energy Centre Ltd | Faversham | 2022 |
| Bottom Plain Solar Park Limited | London | 2012 |
| Boulfruich Wind Farm Limited | Dunbeath | 1997 |
| Bouliac UK Ltd | London | 2025 |
| Boultbee Brooks (Energy Storage Barton in Fabis) Limited | Hereford | 2023 |
| Boultbee Brooks (Energy Storage Borrans Lane) Limited | Hereford | 2024 |
| Boultbee Brooks (Energy Storage Ellbridge Lane) Limited | Hereford | 2023 |
| Boultbee Brooks (Energy Storage Kibworth Road) Limited | Hereford | 2023 |