Vitreous LabsEnergy transparency

Lakeside BESS

105 MW, about 210 MWh (2 hours, from the capacity market de-rating class) in South Lancashire, Yorkshire and Humber. 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 power105 MW balancing mechanism registration
Storage duration2 hours capacity market de-rating class
Charging zoneSouth Lancashire, Yorkshire and Humber
Connection siteDrax 132kV
PostcodeYO8 8FP
Balancing mechanism unitT_LKSDB-1

Who owns it and who trades it

Traded byLakeside Energy Storage Ltdconfirmed, Elexon's register
Owned byLAKESIDE ENERGY STORAGE LIMITED
Owner established fromcapacity market registered holder
UltimatelyTagEnergy confirmed source

How we know. TagEnergy's own energisation announcement.

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 is built from

Battery systemTesla, Megapack 2XL
Power conversionTesla (integrated in Megapack)
Engineering and constructionTesla
Entered operation2024-10
Container count52 to 54 Megapacks (the supplier page states both)
Transformers1 x 80/106 MVA 132/33 kV (Wilson Power); 27 x 4,200 kVA 33 kV MV transformers, dual LV windings
Connection voltage132 kV documented: 80/106 MVA 132/33kV main transformer

From published documents, not from any register: supplier and contractor project pages, owner announcements and the trade press. Confidence: confirmed. Checked 2026-08-30. source 1 · source 2. Fields not shown are not published anywhere we have found, and we do not guess them.

What it earned

Line364 days to 27 September 2026
Balancing mechanism£4.0m
Response and reserve auctions auction implied−£443k
Capacity market£513k
Three lines together£4.1m

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 6,897 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 11 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. 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 out78,972 MWh
Metered import, what crossed the meter in90,140 MWh
Equivalent full cycles, everything sent out over one full charge376 over 346 days, 397 a year at that rate
Apparent meter to meter efficiency88%, an ordinary battery: round trip losses alone
Balancing offers accepted65,688 MWh
Balancing bids accepted40,072 MWh
Position outside balancing, export65,778 MWh
Position outside balancing, import102,562 MWh
Of which expected response delivery, net−26,987 MWh 1,026 out, 28,013 in
Traded position, net−9,796 MWh 71,218 out, 81,014 in
Traded position at the market index, sold£8.6m
Traded position at the market index, bought£6.0m
Traded position, net, at the index£2.6m
Response delivery, net, at the imbalance price−£2.6m −£2.5m at the index
Balancing and outside balancing together£4.0m £40.18/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 £120.61 a megawatt hour at that same index, 1.29 times the average. What it took in was worth £73.84, 0.79 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 40,072 MWh of accepted bids it paid an average of £77.39 a megawatt hour. The market index averaged £107.91 across those same half hours, so it bought back at £30.52 a megawatt hour below the going price.

Price it paidVolumeAverageCash
below zero1,950 MWh−£22.96£45k received
£0 to £252,008 MWh£12.85£26k
£25 to £503,616 MWh£39.76£144k
£50 to £7510,188 MWh£64.60£658k
£75 to £10011,976 MWh£87.83£1.1m
above £10010,335 MWh£122.56£1.3m

On 1,950 MWh the price was below zero: NESO paid this unit an average of £22.96 a megawatt hour to take energy, £45k in all. That is a constrained network with more generation on it than it can move.

The other direction, offers, is much smaller here: 65,688 MWh where NESO asked for more, paid at an average of £108.32 against an index of £79.52.

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/yr93rd percentile98 units
Balancing incomeEngland and Wales peer group90th percentile70 units
Balancing income2.0 hour duration cohort90th percentile61 units
All three measured lineswhole fleet, £/kW/yr84th percentile229 units
Energy sent outhours at full power96th percentile96 units
Energy taken inhours at full power67th 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 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
Thurrock Flexible (THURB-1)1002h£68.1/kW/yr
Dollymans Storage1022h£46.0/kW/yr
Thurrock Flexible (THURB-3)1001.7h£45.8/kW/yr
Lakeside BESSthis battery1052h£39.3/kW/yr
Ferrybridge BESS BMU-1762h£33.0/kW/yr
KXP Immingham BESS812h£12.0/kW/yr

The response line is negative, and that is what the published auction results say. The high direction response services, where a battery commits to absorbing power rather than exporting it, have been clearing below zero, so a unit holding those contracts pays for the position instead of being paid for it.

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.