Vitreous LabsEnergy transparency

Arbroath Battery Storage

34 MW, about 69 MWh (2 hours, from the capacity market de-rating class) in Eastern Grampian and Tayside. 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 power34 MW balancing mechanism registration
Storage duration2 hours capacity market de-rating class
Charging zoneEastern Grampian and Tayside
Connection siteAngus
PostcodeDD11 2QH
Balancing mechanism unitE_ARBRB-1

Who owns it and who trades it

Traded byOctopus Energy Trading Limitedruns several sitesconfirmed, Elexon's register
Owned byARBROATH LIMITED
Owner established fromcapacity market registered holder
UltimatelyGresham House Energy Storage Fund confirmed source

How we know. 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.

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−£652k
Response and reserve auctions auction implied£75k
Capacity market£362k
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 no frequency response contract in the window, so the whole position is treated as traded. 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 out17,752 MWh
Metered import, what crossed the meter in21,462 MWh
Equivalent full cycles, everything sent out over one full charge257 over 346 days, 271 a year at that rate
Apparent meter to meter efficiency83%, plausible: losses plus a standing load that is material against a modest throughput
Balancing offers accepted733 MWh
Balancing bids accepted25,733 MWh
Position outside balancing, export34,610 MWh
Position outside balancing, import13,319 MWh
Valued at the market index, sold£3.4m
Valued at the market index, bought£1.0m
Outside balancing, net, at the index£2.3m
Balancing and outside balancing together£1.7m £52.41/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 £97.26 a megawatt hour at that same index, 1.04 times the average. What it took in was worth £78.55, 0.84 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 25,733 MWh of accepted bids it paid an average of £27.03 a megawatt hour. The market index averaged £88.88 across those same half hours, so it bought back at £61.85 a megawatt hour below the going price.

Price it paidVolumeAverageCash
below zero3,262 MWh−£18.34£60k received
£0 to £255,464 MWh£10.09£55k
£25 to £5014,769 MWh£36.28£536k
£50 to £751,614 MWh£61.30£99k
£75 to £100286 MWh£87.66£25k
above £100339 MWh£119.26£40k

On 3,262 MWh the price was below zero: NESO paid this unit an average of £18.34 a megawatt hour to take energy, £60k in all. That is a constrained network with more generation on it than it can move.

The other direction, offers, is much smaller here: 733 MWh where NESO asked for more, paid at an average of £121.90 against an index of £95.66.

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

Balancing incomewhole fleet, £/kW/yr7th percentile98 units
Balancing incomeScotland peer group11th percentile28 units
Balancing income2.0 hour duration cohort3rd percentile61 units
All three measured lineswhole fleet, £/kW/yr28th percentile229 units
Energy sent outhours at full power15th percentile96 units
Energy taken inhours at full power92nd 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 Scotland, 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
Wishaw BESS512h£44.7/kW/yr
Auchteraw492h£33.3/kW/yr
Erskine BESS302h£11.1/kW/yr
East Ayrshire (KILSB-2)522h£3.1/kW/yr
Shilton Lane BESS402h£2.2/kW/yr
Arbroath Battery Storagethis battery342hnot netted

The three lines are not added together for this site. It paid £742k to charge and the lines we can measure paid it £527k. 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. Sites in this position are usually constraint assets, paid to absorb wind the network cannot move south.

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.