Coupar Battery Storage
41 MW, about 83 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 power | 41 MW balancing mechanism registration |
| Storage duration | 2 hours capacity market de-rating class |
| Charging zone | Eastern Grampian and Tayside |
| Connection site | Perth and Kinross |
| Postcode | PH13 9JB |
| Balancing mechanism unit | E_CUPAB-1 |
Who owns it and who trades it
| Traded by | Octopus Energy Trading Limitedruns several sitesconfirmed, Elexon's register |
| Owned by | COUPAR LIMITED |
| Owner established from | capacity market registered holder |
| Ultimately | Gresham 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
| Line | 364 days to 27 September 2026 |
|---|---|
| Balancing mechanism | −£774k |
| Response and reserve auctions auction implied | £88k |
| Capacity market | £318k |
| Three lines together | not 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
| Line | MWh or £ |
|---|---|
| Metered export, what crossed the meter out | 27,442 MWh |
| Metered import, what crossed the meter in | 32,657 MWh |
| Equivalent full cycles, everything sent out over one full charge | 332 over 346 days, 350 a year at that rate |
| Apparent meter to meter efficiency | 84%, an ordinary battery: round trip losses alone |
| Balancing offers accepted | 574 MWh |
| Balancing bids accepted | 25,004 MWh |
| Position outside balancing, export | 43,044 MWh |
| Position outside balancing, import | 23,829 MWh |
| Valued at the market index, sold | £4.7m |
| Valued at the market index, bought | £1.9m |
| Outside balancing, net, at the index | £2.9m |
| Balancing and outside balancing together | £2.2m £55.22/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 £110.01 a megawatt hour at that same index, 1.18 times the average. What it took in was worth £78.60, 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 25,004 MWh of accepted bids it paid an average of £30.91 a megawatt hour. The market index averaged £96.34 across those same half hours, so it bought back at £65.43 a megawatt hour below the going price.
| Price it paid | Volume | Average | Cash |
|---|---|---|---|
| below zero | 2,722 MWh | −£20.36 | £55k received |
| £0 to £25 | 6,187 MWh | £11.56 | £72k |
| £25 to £50 | 11,558 MWh | £34.24 | £396k |
| £50 to £75 | 2,538 MWh | £60.61 | £154k |
| £75 to £100 | 971 MWh | £86.67 | £84k |
| above £100 | 1,027 MWh | £119.55 | £123k |
On 2,722 MWh the price was below zero: NESO paid this unit an average of £20.36 a megawatt hour to take energy, £55k in all. That is a constrained network with more generation on it than it can move.
The other direction, offers, is much smaller here: 574 MWh where NESO asked for more, paid at an average of £125.87 against an index of £95.23.
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/yr | 5th percentile98 units | |
| Balancing incomeScotland peer group | 7th percentile28 units | |
| Balancing income2.0 hour duration cohort | 2nd percentile61 units | |
| All three measured lineswhole fleet, £/kW/yr | 23rd percentile229 units | |
| Energy sent outhours at full power | 11th percentile96 units | |
| Energy taken inhours at full power | 86th 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.
| Battery | MW | Hours | Measured, per kW |
|---|---|---|---|
| Wishaw BESS | 51 | 2h | £44.7/kW/yr |
| Auchteraw | 49 | 2h | £33.3/kW/yr |
| Erskine BESS | 30 | 2h | £11.1/kW/yr |
| East Ayrshire (KILSB-2) | 52 | 2h | £3.1/kW/yr |
| Shilton Lane BESS | 40 | 2h | £2.2/kW/yr |
| Coupar Battery Storagethis battery | 41 | 2h | not netted |
The three lines are not added together for this site. It paid £859k to charge and the lines we can measure paid it £491k. 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
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.