Vitreous LabsEnergy transparency

West Burton B Battery (WBURB-41)

31 MW, about 28 MWh (0.9 hours, measured from its behaviour) in North Midlands and North Wales. Everything on this page is read from published data for the 364 days to 27 September 2026, or is labelled as an estimate.

Part of West Burton B Battery, one of 2 balancing units at one site totalling 62 MW. This page is the T_WBURB-41 unit alone.

What it is

Registered power31 MW balancing mechanism registration
Storage duration0.9 hours measured from twenty one days of behaviour
Charging zoneNorth Midlands and North Wales
Balancing mechanism unitT_WBURB-41

Who owns it and who trades it

Traded byWest Burton B Limitedconfirmed, Elexon's register
Owned bynot published anywhere we can read
UltimatelyUK Transition Power confirmed source

How we know. West Burton B Limited is controlled by UK Transition Power Limited, which has been held by West Burton Flexible Generation Ltd since October 2025 and by UK T-Power 2 Limited, now in liquidation, before that. EDF Energy (Thermal Generation) Limited held West Burton B until August 2021. What sits above West Burton Flexible Generation has not been read.

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 mechanism−£12k
Response and reserve auctions auction implied£0
Capacity marketno agreement we can attach
Three lines togethernot netted

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 15,462 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 out2,299 MWh
Metered import, what crossed the meter in4,147 MWh
Equivalent full cycles, everything sent out over one full charge82.4 over 346 days, 86.9 a year at that rate
Apparent meter to meter efficiency55%, not ordinary battery losses alone
Balancing offers accepted477 MWh
Balancing bids accepted1,244 MWh
Position outside balancing, export2,507 MWh
Position outside balancing, import3,589 MWh
Of which expected response delivery, net88 MWh 660 out, 572 in
Traded position, net−1,170 MWh 2,211 out, 3,381 in
Traded position at the market index, sold£236k
Traded position at the market index, bought£289k
Traded position, net, at the index−£52k
Response delivery, net, at the imbalance price£3k £6k at the index
Balancing and outside balancing together−£67k £-2.29/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 £106.97 a megawatt hour at that same index, 1.15 times the average. What it took in was worth £85.48, 0.92 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.

What it paid to buy energy back

When NESO accepts a bid, this unit delivers less than it had already sold, or takes more in. It pays for the energy it no longer delivers, and that payment is most of what makes the balancing figure above negative. Whether that is a cost or a margin depends on the price it paid. Across 1,244 MWh of accepted bids it paid an average of £69.69 a megawatt hour. The market index averaged £99.39 across those same half hours, so it bought back at £29.70 a megawatt hour below the going price.

Price it paidVolumeAverageCash
below zero161 MWh−£25.38£4k received
£0 to £2586 MWh£11.78£1k
£25 to £50124 MWh£37.70£5k
£50 to £75206 MWh£62.98£13k
£75 to £100264 MWh£84.36£22k
above £100403 MWh£123.76£50k

On 161 MWh the price was below zero: NESO paid this unit an average of £25.38 a megawatt hour to take energy, £4k in all. That is a constrained network with more generation on it than it can move.

The other direction, offers, is much smaller here: 477 MWh where NESO asked for more, paid at an average of £145.21 against an index of £111.30.

Checks this unit did not pass cleanly. Published anyway, because a flagged figure with its flag is more use than a blank.

  • returns only 55% of what it takes in, with 2,298 MWh exported all year, about 74 full power hours: a unit that barely cycles, where its own standing consumption and losses dominate a small throughput

Where it stands

Balancing incomewhole fleet, £/kW/yr8th percentile98 units
Balancing incomeEngland and Wales peer group6th percentile70 units
Balancing income0.9 hour duration cohort4th percentile24 units
All three measured lineswhole fleet, £/kW/yr13th percentile229 units
Energy sent outhours at full power13th percentile96 units
Energy taken inhours at full power8th percentile96 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. They run for about the same length of time. Same market, same rules, same weather.

BatteryMWHoursMeasured, per kW
Aylesford301h£84.5/kW/yr
Port of Tyne Energy Storage350.7h£62.2/kW/yr
Zenobe Capenhurst (PINFB-1)271h£53.4/kW/yr
West Burton B Battery (WBURB-43)310.5h£46.8/kW/yr
Loudwater331h£32.9/kW/yr
West Burton B Battery (WBURB-41)this battery310.9hnot netted

The three lines are not added together for this site. It paid £97k to charge and the lines we can measure paid it £85k. The energy it bought was sold in the wholesale market and nothing published measures that sale, so subtracting one from the other would show a loss it does not make.

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.