Vitreous LabsEnergy transparency

Gresham House Energy Storage Fund

Owns 26 batteries at 26 sites, 812 MW, which is 10.4 per cent of everything operating in Great Britain. It sells none of that power itself. The register names 8 other companies as the sellers: Habitat Energy Limited, Octopus Energy Trading Limited, Arenko Cleantech Limited and 5 others.

26batteries, counting a re-registered battery once
812 MWof the 7,779 MW operating fleet
£32/kW/yrpaid across the three measured lines, against £42 for the whole fleet
25 of 26confirmed on a control filing or the owner's own statement, the rest 1 probable

Who sells its power

The balancing mechanism register names the company allowed to sell each unit's power. That company is usually an optimiser or a supplier working under contract, which is why the registers cannot answer the ownership question on their own. Where the seller is one of the owner's own companies, the row says so.

Habitat Energy Limited 349 MW · Octopus Energy Trading Limited 272 MW · Arenko Cleantech Limited 65 MW · BGI Trading Limited 45 MW · others 81 MW

What it was paid

The three published lines, added up across the fleet for the 364 days to 27 September 2026. Wholesale trading income is invisible for every owner, not just this one, and nothing here nets the cost of charging. The rate is per kilowatt of current capacity.

Balancing mechanism, paid to discharge£1.6m
Balancing mechanism, paid out to charge−£2.2m
Response and reserve auctions£14.5m
Capacity market£10.0m
Income across the fleet, per kilowatt£32.28/kW/yr fleet 42.17
Median battery, all three lines£13.66/kW/yr
Hours at full power, sent out65 h/yr
Hours at full power, taken in309 h/yr

What the fleet is made of

Duration, by megawatt

about 1 hour 203 MW · about 1.5 hours 40 MW · 2 hours and up 462 MW · not published 107 MW

Region, by megawatt

Scotland 144 MW · England and Wales 668 MW

Every battery it owns

BatteryMWSold byGrade£/kW/yr
Grendon
Mid Wales and The Midlands
50Habitat Energy Limitedconfirmed76.32
Melksham East
Cotswold
49Habitat Energy Limitedconfirmed107.34
Red Scar
South Lancashire, Yorkshire and Humber
49Habitat Energy Limitedconfirmed13.66
Wickham Market
Mid Wales and The Midlands
49Habitat Energy Limitedconfirmed6.31
York
South Lancashire, Yorkshire and Humber
49Habitat Energy Limitedconfirmed52.97
Melksham West
Cotswold
49Habitat Energy Limitedconfirmed37.33
Enderby
Mid Wales and The Midlands
45BGI Trading Limitedconfirmed35.07
West Didsbury
North Midlands and North Wales
45Octopus Energy Trading Limitedconfirmed14.64
AR0006-BLOX
Mid Wales and The Midlands
42Octopus Energy Trading Limitedconfirmed23.33
Coupar Battery Storage
Eastern Grampian and Tayside
41Octopus Energy Trading Limitedconfirmed11.92
Shilton Lane BESS
South West Scotland
40Octopus Energy Trading Limitedconfirmed6.04
Stairfoot
North Midlands and North Wales
40Octopus Energy Trading Limitedconfirmed10.01
Glassenbury
Essex and Kent
40Habitat Energy Limitedprobable0.00
Port of Tyne Energy Storage
North East England
35Arenko Cleantech Limitedconfirmed65.99
Arbroath Battery Storage
Eastern Grampian and Tayside
34Octopus Energy Trading Limitedconfirmed15.32
West Bradford
South Lancashire, Yorkshire and Humber
29Octopus Energy Trading Limitedconfirmed29.42
Byers Brae (EDF01N)
Stirlingshire and Fife
28EDF Energy Limitedconfirmed14.80
Carnegie Road 1
North Midlands and North Wales
20Arenko Cleantech Limitedconfirmed59.66
Roundponds Storage
Cotswold
16Equinicity LTDconfirmed−14.29
Lockleaze
Cotswold
15Equinicity LTDconfirmed−2.78
Nevendon
Essex and Kent
10Arenko Cleantech Limitedconfirmed13.25
Glassenbury extension
Essex and Kent
9Habitat Energy Limitedconfirmed30.55
Littlebrook
Essex and Kent
8Anesco Limitedconfirmed28.46
Cleator Storage
North Lancashire and The Lakes
8Statkraft Markets GmbHconfirmed36.48
Rufford
North Midlands and North Wales
6Equinicity LTDconfirmed−6.59
Wolverhampton
Mid Wales and The Midlands
5Habitat Energy Limitedconfirmed4.08

5 batteries ran under an earlier registration for part of the year, BFSE01, BYBRB-1, HAB5-FFR, MNOR-01, NFSE02. The money earned under the earlier code is in the book above; the capacity is counted once.

How we know

Confirmed means a control filing at Companies House, or the owner's own published statement, names the company. Probable means the evidence is strong and indirect. Named means the register leaves the owner blank, the balancing code carries the owner's initials, and a sibling unit at the same site is already settled. Each chain below is printed once, with the batteries it settles.

Confirmed York, AR0006-BLOX, Coupar Battery Storage, Arbroath Battery Storage, West Bradford, Byers Brae (EDF01N), Carnegie Road 1, Glassenbury extension, Cleator Storage, Wolverhampton
The registered office of each company names Gresham House Asset Management, read company by company on 31 August 2026. The address alone would not settle it, because 875 companies sit at 5 New Street Square; the care of line naming the manager is the discriminator. Source

Confirmed Red Scar, Wickham Market, Roundponds Storage, Littlebrook
Each HC ESS company is registered care of Gresham House Asset Management. The control filing on HC ESS4 runs to Grid Holdco 1 Limited since 22 August 2025, and Grid Holdco 1 is held in turn by Gresham House Energy Storage Holdings Limited. Source

Confirmed Grendon
Statera's Grendon page names Gresham House Energy Storage Fund plc as project owner, with Statera as developer, EPC and O&M. Source

Confirmed Melksham East
Statera's Melksham East page names Gresham House Energy Storage Fund plc as project owner, with Statera as developer, EPC and O&M. Source

Confirmed Melksham West
Statera's Melksham West page names the fund as owner; Habitat's virtual unit V__HHABI019 is registered as Melksham West. Source

Confirmed Port of Tyne Energy Storage, Nevendon
The fund announced buying Port of Tyne and Nevendon on 1 February 2021. Source

Confirmed Enderby
Statera's Enderby page names Gresham House Energy Storage Fund plc as project owner, with Statera as developer, EPC and O&M. Source

Confirmed West Didsbury
Statera's West Didsbury page names Gresham House Energy Storage Fund plc as project owner, with Statera as developer, EPC and O&M. Source

Confirmed Shilton Lane BESS
The register names no owner. Gresham House bought the 40 MW Shilton Lane project near Glasgow in 2022, and the capacity market holds three Shilton agreements at that location belonging to Gresham House Energy Storage Holdings plc. Source

Confirmed Stairfoot
The SPV is registered c/o Gresham House Asset Management (Ofgem licence notice, November 2022). Source

Confirmed Mnor-01 (earlier registration)
The register names no owner. The capacity market holds Stairfoot 1 belonging to Gresham House Energy Storage Fund plc 70 metres away, and Stairfoot Generation Ltd is already confirmed to the fund. Source

Confirmed West Lothian (earlier registration)
The register names no owner. The capacity market holds Byers Brae Battery Storage belonging to Gresham House Energy Storage Holdings plc 880 metres away. Source

Confirmed Byers Brae (BYBRB-1) (earlier registration)
The register names no owner and NESO places the code at Arbroath, DD11 2QH. The code stem, the dates and Octopus's Elexon unit named Byers Brae say it is Byers Brae, the fund's West Lothian battery, which EDF01N took over two days after this code was last paid (gb/fleet_joins.py, 26 September 2026); either way it is the fund's. Source

Confirmed Lockleaze
The register names no owner. The capacity market holds the Alpha site belonging to HC ESS2 Holdco Limited 110 metres away, and HC ESS2 is a Gresham House company. Source

Confirmed Rufford
The register names no owner. The fund's factsheet of 31 December 2024 lists Rufford, Nottinghamshire, 7 MW, and its 2025 annual report names Rufford among the five assets bought at the IPO; RUFF-1 is 6 MW at NG21 0HR, Rufford, sold by Equinicity like the fund's other seed assets LNOR-01 and HNOR-01. Source

Probable Bfse01 (earlier registration)
The register names no owner. The capacity market holds the Enderby Storage agreements 260 metres away in the name of Statera Energy Limited, and Statera's own Enderby page names Gresham House Energy Storage Fund plc as the owner with Statera as developer. Source

Probable Glassenbury
The register names no owner and places this unit only by postcode district. Glassenbury Storage, a Gresham House Energy Storage Fund plc site of about the same size, sits inside that district, and the smaller Glassenbury unit is already confirmed to the fund. Source

Probable Cumberland (earlier registration)
The register names no owner and places this unit only by postcode district. Cleator Storage, a Gresham House Energy Storage Fund plc site, sits inside that district, and the other Cleator unit is already confirmed to the fund. Source

Attribution. A battery belongs to whoever the documents name today, so a fleet that changed hands during the year credits the whole year to the current owner. Groups are joined only where a filing joins them; a company that holds through several vehicles appears once, under the name at the top of the chain. Directors and registered offices are never used as evidence on their own. Why the registers cannot answer this question

All owners