Vitreous LabsEnergy transparency

ZEN02A

20 MW in Mid Wales and The Midlands. Everything on this page is read from published data for the 364 days to 27 September 2026, or is labelled as an estimate.

What it is

Registered power20 MW response and reserve auction registration
Charging zoneMid Wales and The Midlands
Connection siteBabergh
PostcodeCO10
Balancing mechanism unitnone found under the codes we search

Who owns it and who trades it

Traded byBESS Holdco 2 Limitedconfirmed, Elexon's register
Owned bynot published anywhere we can read
UltimatelyZenobe Energy confirmed source

How we know. The register names no owner. The capacity market holds a site called Claredown belonging to Bess Holdco 4 Limited, the renewables planning database gives Claredown Farm to Zenobe under its former name Energy Reservoir 15 at the same 20 MW, and the Bess Holdco companies run through IFM Master Holdco Limited to Zenobe Energy Limited.

Market registers name the party that sells into the market, which for a battery is usually an optimiser under contract rather than the owner. Elexon's balancing mechanism unit register names the seller here and the name is checked against it on every build. How we tell them apart

What it earned

Line364 days to 27 September 2026
Balancing mechanismnot published
Response and reserve auctions auction implied£1.7m
Capacity marketno agreement we can attach
Three lines together£1.7m

Balancing is offer revenue and does not net off the cost of the power. The response and reserve figure is the value implied by the published auction results, award quantity times clearing price times the length of the delivery window, and not a settled payment. Capacity market income is the cleared price raised for inflation where the auction set a base period, split by month on EMRS's weights. Method

Outside the balancing mechanism, derived from the meter

Elexon publishes what this unit's meter recorded every half hour. Take away the balancing volumes NESO accepted and what is left is the position the unit ran outside the balancing mechanism: its wholesale trading, its frequency response delivery, and its losses, together. This unit held a frequency response contract in 15,925 of those half hours. The energy the contract asked of it, contracted megawatts times NESO's published delivery curve at the measured grid frequency, is taken out of the position and valued at the imbalance price, because it sits outside the unit's declared position and that is the price Elexon settles it at. What remains is the traded position, valued at the market index. In 17 half hours a contract was held but the grid frequency is not yet held, so those are left in the traded position. The volumes are measured. The prices are public benchmarks, not this unit's trades. The product is derived, and is shown apart from the three measured lines above. 346 days to 12 September 2026, 33 of them still provisional in Elexon's settlement runs. Method and caveats

LineMWh or £
Metered export, what crossed the meter out7,858 MWh
Metered import, what crossed the meter in9,778 MWh
Equivalent full cycles, everything sent out over one full charge·
Apparent meter to meter efficiency80%, plausible: losses plus a standing load that is material against a modest throughput
Balancing offers accepted0 MWh
Balancing bids accepted0 MWh
Position outside balancing, export7,858 MWh
Position outside balancing, import9,778 MWh
Of which expected response delivery, net13,659 MWh 13,895 out, 236 in
Traded position, net−15,579 MWh 1,522 out, 17,101 in
Traded position at the market index, sold£140k
Traded position at the market index, bought£1.6m
Traded position, net, at the index−£1.5m
Response delivery, net, at the imbalance price£1.2m £1.3m at the index
Balancing and outside balancing together−£227k £-11.99/kW/yr

When it moved, against when power was dear

Across every half hour this unit was metered the market index averaged £93.43. What it sent out was worth £91.87 a megawatt hour at that same index, 0.98 times the average. What it took in was worth £94.09, 1.01 times. Selling above one and buying below one is a unit positioned into the dear half hours and out of the cheap ones. It measures the half hours it chose, not the price anyone paid it, which is not published.

Physical checks passed: the meter never exceeded the registered power by more than fifteen per cent, and the year's exports against imports are what a battery does.

Where it stands

All three measured lineswhole fleet, £/kW/yr89th percentile229 units

Percentiles, so 90 means better than nine in ten of the cohort named beside it, on that measure alone, over the same 364 days. Rates are pounds per kilowatt per year, annualised over the days the unit has been on the system, the same figures the performance league ranks on. A high position in the taken-in table is not a fault: a constraint asset is paid to charge, and charging is its job.

The nearest comparables

The five nearest in size in England and Wales, and this battery among them, ranked by what each was paid for every kilowatt it holds over the 364 days to the same date. How long this battery can run for is not published, so duration is not used to choose them. Same market, same rules, same weather.

BatteryMWHoursMeasured, per kW
ZEN02Athis battery20not known£85.8/kW/yr
Oldham BESS202h£81.1/kW/yr
Carnegie Road 1202h£54.9/kW/yr
Farnham BESS202h£45.5/kW/yr
Hawkers Hill Battery202h£38.0/kW/yr
Gerrards Cross BESS201h£37.0/kW/yr

See it on the map

Open the operating map here

Every figure on this page traces to a published file. If something here is wrong about your asset, the methods section says how to tell us.