Vitreous LabsEnergy transparency

Downing

Owns 1 battery at 1 site, 48 MW, which is 0.7 per cent of everything operating in Great Britain. It sells none of that power itself. The register names one seller for the whole fleet, EDF Energy Customers Limited.

1batteries, counting a re-registered battery once
48 MWof the 6,849 MW operating fleet
£37/kW/yrpaid across the three measured lines, against £35 for the whole fleet
1 of 1confirmed on a control filing or the owner's own statement

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.

EDF Energy Customers Limited 48 MW
SellerBatteriesMWOf this fleet
EDF Energy Customers Limited148100%

What it was paid

The three published lines, added up across the fleet for the 364 days to 6 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£472k
Balancing mechanism, paid out to charge−£335k
Response and reserve auctions£1.2m
Capacity market£73k
Income across the fleet, per kilowatt£37.28/kW/yr fleet 35.48
Median battery, all three lines£37.28/kW/yr
Hours at full power, sent out92 h/yr
Hours at full power, taken in103 h/yr

What the fleet is made of

Duration, by megawatt

about 1 hour 48 MW

Region, by megawatt

England and Wales 48 MW

Every battery it owns

BatteryMWSold byGrade£/kW/yr
Nursling Battery Storage
Somerset and Wessex
48EDF Energy Customers Limitedconfirmed37.28

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 Nursling Battery Storage
Downing's own portfolio names Nursling Energy Two Limited, which the connection register carries as Nursling Tertiary at Nursling 400kV, built. A Downing Group member joined both Nursling boards in July 2026. Note that Downing Corporate Finance ceased to control the parent in March 2019: it is now held between Bagnall Energy Limited and CCPEPF UK Intermediate Limited, each between a quarter and a half, and both file that they have no registrable controller. Downing is the manager here, and the register names no single controlling company. 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