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Great Britain · the operating fleet

Tiln

25 MW, about 50 MWh (2 hours, from the capacity market de-rating class) in North Midlands and North Wales. Everything on this page is read from published data for the 364 days to 16 October 2026, or is labelled as an estimate.

What it is

Registered power25 MW response and reserve auction registration
Storage duration2 hours capacity market de-rating class
Charging zoneNorth Midlands and North Wales
Connection siteBassetlaw
PostcodeDN22 9JH
Balancing mechanism unit2__BFLEX004 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 byFlexitricity Limitedruns several sitesconfirmed, Elexon's register
Owned bySG GRI TILN BESS LIMITED
Owner established fromcapacity market registered holder

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£433k
Response and reserve auctions auction implied£593k
Capacity market£122k
Three lines together£1.1m

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 9,328 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 15 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. 359 days to 11 October 2026, 45 of them still provisional in Elexon's settlement runs. Method and caveats

LineMWh or £
Metered export, what crossed the meter out17,298 MWh
Metered import, what crossed the meter in19,790 MWh
Equivalent full cycles, everything sent out over one full charge346 over 359 days, 352 a year at that rate
Apparent meter to meter efficiency87%, an ordinary battery: round trip losses alone
Balancing offers accepted5,593 MWh
Balancing bids accepted4,551 MWh
Position outside balancing, export16,171 MWh
Position outside balancing, import19,705 MWh
Of which expected response delivery, net−1,238 MWh 962 out, 2,200 in
Traded position, net−2,297 MWh 16,219 out, 18,516 in
Traded position at the market index, sold£2.0m
Traded position at the market index, bought£1.5m
Traded position, net, at the index£562k
Response delivery, net, at the imbalance price−£169k −£152k at the index
Balancing and outside balancing together£775k £31.54/kW/yr

When it moved, against when power was dear

Across every half hour this unit was metered the market index averaged £97.34. What it sent out was worth £124.96 a megawatt hour at that same index, 1.28 times the average. What it took in was worth £79.14, 0.81 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 4,551 MWh of accepted bids it paid an average of £72.38 a megawatt hour. The market index averaged £111.33 across those same half hours, so it bought back at £38.95 a megawatt hour below the going price.

Price it paidVolumeAverageCash
below zero393 MWh−£21.47£8k received
£0 to £25405 MWh£12.54£5k
£25 to £50725 MWh£37.63£27k
£50 to £75675 MWh£62.98£42k
£75 to £100842 MWh£88.81£75k
above £1001,511 MWh£124.54£188k

On 393 MWh the price was below zero: NESO paid this unit an average of £21.47 a megawatt hour to take energy, £8k in all. That is a constrained network with more generation on it than it can move.

The other direction, offers, is much smaller here: 5,593 MWh where NESO asked for more, paid at an average of £127.36 against an index of £86.65.

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/yr69th percentile230 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
Equinor Blandford Road231.5h£134.3/kW/yr
Blackpool252h£49.4/kW/yr
Tilnthis battery252h£46.1/kW/yr
Charnock Richard272.5h£35.5/kW/yr
Whitebirk BESS252h£32.6/kW/yr
Torquay222h£28.2/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.