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Great Britain · the operating fleet

Byers Brae (BYBRB-1)

26 MW in Stirlingshire and Fife. Everything on this page is read from published data for the 364 days to 16 October 2026, or is labelled as an estimate.

This registration has been superseded. The battery here has sold as Byers Brae (EDF01N) since 21 August 2026; this code, sold by OCTOPUS ENERGY TRADING LIMITED, last appeared on 19 August 2026. The page stays for the record, and the unit is no longer counted in fleet totals or ranked in the league.

What it is

Registered power26 MW response and reserve auction registration
Charging zoneStirlingshire and Fife
Connection siteWest Lothian
PostcodeEH48 1JY
Balancing mechanism unit2__NCPPR001 a supplier unit registered by the company that trades it; its balancing actions are counted on this page

Who owns it and who trades it

Traded byOCTOPUS ENERGY TRADING LIMITEDruns several sitesconfirmed, Elexon's register
Owned bynot published anywhere we can read
UltimatelyGresham House Energy Storage Fund confirmed source

How we know. 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.

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 16 October 2026
Balancing mechanism−£90k
Response and reserve auctions auction implied£101k
Capacity marketno agreement we can attach
Three lines together£10k

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. 339 days to 21 September 2026, 25 of them still provisional in Elexon's settlement runs. Method and caveats

LineMWh or £
Metered export, what crossed the meter out0 MWh
Metered import, what crossed the meter in0 MWh
Equivalent full cycles, everything sent out over one full charge·
Apparent meter to meter efficiency·
Balancing offers accepted432 MWh
Balancing bids accepted5,631 MWh
Position outside balancing, export5,620 MWh
Position outside balancing, import421 MWh
Valued at the market index, sold£471k
Valued at the market index, bought£41k
Outside balancing, net, at the index£430k
Balancing and outside balancing together£340k £14.08/kW/yr

When it moved, against when power was dear

Across every half hour this unit was metered the market index averaged £94.88. What it sent out was worth £83.77 a megawatt hour at that same index, 0.88 times the average. What it took in was worth £96.37, 1.02 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 5,631 MWh of accepted bids it paid an average of £25.90 a megawatt hour. The market index averaged £83.80 across those same half hours, so it bought back at £57.90 a megawatt hour below the going price.

Price it paidVolumeAverageCash
below zero953 MWh−£18.62£18k received
£0 to £251,312 MWh£12.49£16k
£25 to £502,674 MWh£34.95£93k
£50 to £75429 MWh£60.45£26k
£75 to £100134 MWh£87.43£12k
above £100130 MWh£124.53£16k

On 953 MWh the price was below zero: NESO paid this unit an average of £18.62 a megawatt hour to take energy, £18k in all. That is a constrained network with more generation on it than it can move.

The other direction, offers, is much smaller here: 432 MWh where NESO asked for more, paid at an average of £129.05 against an index of £96.40.

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.

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. 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
South Redhouse161h£30.5/kW/yr
Byers Brae (EDF01N)281h£22.1/kW/yr
Shilton Lane BESS402h£2.3/kW/yr
Erskine BESS302h£1.9/kW/yr
Byers Brae (BYBRB-1)this battery26not known£0.4/kW/yr
West Lothian29not known£0.0/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.