Wilton BESS (LIONB-2)
50 MW in Great Britain. 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 | 50 MW balancing mechanism registration |
| Balancing mechanism unit | T_LIONB-2 |
Who owns it and who trades it
| Traded by | Sembcorp (Wilton BESS) Ltdconfirmed, Elexon's register |
| Owned by | not published anywhere we can 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
| Line | 364 days to 27 September 2026 |
|---|---|
| Balancing mechanism | £14k |
| Response and reserve auctions auction implied | £0 |
| Capacity market | no agreement we can attach |
| Three lines together | £14k |
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. 88 days to 12 September 2026, 32 of them still provisional in Elexon's settlement runs. Method and caveats
| Line | MWh or £ |
|---|---|
| Metered export, what crossed the meter out | 1,832 MWh |
| Metered import, what crossed the meter in | 2,486 MWh |
| Equivalent full cycles, everything sent out over one full charge | · |
| Apparent meter to meter efficiency | 74%, worth investigating: more than ordinary losses |
| Balancing offers accepted | 0 MWh |
| Balancing bids accepted | 0 MWh |
| Position outside balancing, export | 1,832 MWh |
| Position outside balancing, import | 2,486 MWh |
| Valued at the market index, sold | £190k |
| Valued at the market index, bought | £257k |
| Outside balancing, net, at the index | −£66k |
| Balancing and outside balancing together | −£66k £-5.50/kW/yr |
When it moved, against when power was dear
Across every half hour this unit was metered the market index averaged £116.56. What it sent out was worth £103.90 a megawatt hour at that same index, 0.89 times the average. What it took in was worth £103.27, 0.89 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.
Checks this unit did not pass cleanly. Published anyway, because a flagged figure with its flag is more use than a blank.
- only 88 of 364 days metered
Where it stands
| All three measured lineswhole fleet, £/kW/yr | 12th percentile229 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. How long this battery can run for is not published, so duration is not used to choose them. Same market, same rules, same weather.
| Battery | MW | Hours | Measured, per kW |
|---|---|---|---|
| Grendon | 50 | 2h | £76.3/kW/yr |
| Creyke Beck | 50 | not known | £65.2/kW/yr |
| Pelham | 50 | 1h | £60.2/kW/yr |
| Minety South | 50 | 1h | £55.4/kW/yr |
| Wilton BESS (LIONB-1) | 50 | not known | £0.5/kW/yr |
| Wilton BESS (LIONB-2)this battery | 50 | not known | £0.3/kW/yr |
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.