How it is computed
For a 2-hour battery, within one day: charge in the cheapest 8 quarter-hours, discharge in the most expensive 8. Margin, per MWh delivered:
margin = discharge_price − charge_price / 0.85 − tariffs
Divided by efficiency, not multiplied: to deliver 1 MWh you must buy 1,1765 MWh. The remaining 0,1765 MWh is lost, and the extraction tariff is owed on it.
RO · RON/MWh delivered
Figures are in RON, the currency in which the zone publishes its price. Not comparable across zones without conversion — the same rule as for forecast error.
Network tariffs deducted: 12,66 RON/MWh delivered (ANRE 01.01.2026), storage exemption active. Without the exemption it would be ~5× more.
Wear threshold: 87,2 RON/MWh ·
efficiency 0.85
2-hour battery
| Month | Days | Median | P10 | P90 | Days below threshold | Top 10% of days |
|---|
| 2024-12 | 1 | 838,6 | 838,6 | 838,6 | 0 | 100,0% |
| 2025-01 | 31 | 370,3 | 220,0 | 781,7 | 0 | 33,9% |
| 2025-02 | 28 | 489,5 | 221,9 | 1.155,7 | 0 | 25,4% |
| 2025-03 | 31 | 730,5 | 362,9 | 1.173,8 | 0 | 18,2% |
| 2025-04 | 30 | 789,1 | 415,3 | 1.059,8 | 0 | 17,4% |
| 2025-05 | 31 | 788,3 | 523,0 | 1.305,0 | 0 | 16,4% |
| 2025-06 | 30 | 941,2 | 752,5 | 1.073,9 | 0 | 15,6% |
| 2025-07 | 31 | 636,6 | 402,6 | 1.132,8 | 0 | 22,2% |
| 2025-08 | 31 | 824,2 | 566,1 | 1.076,8 | 0 | 15,5% |
| 2025-09 | 30 | 942,1 | 502,4 | 1.393,7 | 0 | 17,0% |
| 2025-10 | 31 | 865,1 | 534,1 | 1.297,7 | 0 | 19,1% |
| 2025-11 | 30 | 544,5 | 197,1 | 1.011,2 | 0 | 23,6% |
| 2025-12 | 31 | 303,3 | 130,6 | 721,5 | 0 | 26,4% |
| 2026-01 | 31 | 497,9 | 131,5 | 1.348,4 | 0 | 25,1% |
| 2026-02 | 28 | 501,6 | 214,7 | 744,6 | 0 | 20,3% |
| 2026-03 | 31 | 859,5 | 602,3 | 1.152,4 | 0 | 15,3% |
| 2026-04 | 30 | 911,8 | 555,4 | 1.133,4 | 0 | 14,9% |
| 2026-05 | 31 | 1.085,0 | 702,4 | 1.301,6 | 0 | 14,8% |
| 2026-06 | 30 | 984,9 | 448,1 | 2.555,4 | 0 | 27,6% |
| 2026-07 | 31 | 871,6 | 756,1 | 1.204,1 | 0 | 18,2% |
| 2026-08 | 31 | 951,1 | 470,5 | 1.446,2 | 0 | 18,1% |
Median by duration
| Month | 1h | 2h | 4h |
|---|
| 2024-12 | 1.125,0 | 838,6 | 578,5 |
| 2025-01 | 374,4 | 370,3 | 324,4 |
| 2025-02 | 532,1 | 489,5 | 403,1 |
| 2025-03 | 745,5 | 730,5 | 610,1 |
| 2025-04 | 864,2 | 789,1 | 698,6 |
| 2025-05 | 879,3 | 788,3 | 722,1 |
| 2025-06 | 1.047,3 | 941,2 | 797,4 |
| 2025-07 | 649,0 | 636,6 | 507,5 |
| 2025-08 | 879,9 | 824,2 | 696,7 |
| 2025-09 | 1.022,0 | 942,1 | 811,7 |
| 2025-10 | 919,6 | 865,1 | 708,4 |
| 2025-11 | 636,9 | 544,5 | 405,9 |
| 2025-12 | 351,1 | 303,3 | 263,6 |
| 2026-01 | 565,4 | 497,9 | 426,0 |
| 2026-02 | 523,0 | 501,6 | 449,9 |
| 2026-03 | 938,4 | 859,5 | 773,2 |
| 2026-04 | 1.025,8 | 911,8 | 811,0 |
| 2026-05 | 1.164,8 | 1.085,0 | 899,0 |
| 2026-06 | 1.099,0 | 984,9 | 882,9 |
| 2026-07 | 931,0 | 871,6 | 798,4 |
| 2026-08 | 993,4 | 951,1 | 892,9 |
BG · EUR/MWh delivered
Figures are in EUR, the currency in which the zone publishes its price. Not comparable across zones without conversion — the same rule as for forecast error.
Before network tariffs. We do not have this zone's regulated tariffs, so the margin is before them. We do not assume them.
Wear threshold: 17,4 EUR/MWh ·
efficiency 0.85
2-hour battery
| Month | Days | Median | P10 | P90 | Days below threshold | Top 10% of days |
|---|
| 2025-10 | 31 | 173,8 | 109,7 | 257,5 | 0 | 18,9% |
| 2025-11 | 30 | 109,5 | 41,2 | 201,3 | 0 | 23,4% |
| 2025-12 | 31 | 66,3 | 28,2 | 144,2 | 0 | 24,8% |
| 2026-01 | 31 | 100,7 | 28,3 | 269,7 | 0 | 25,5% |
| 2026-02 | 28 | 100,8 | 44,6 | 147,2 | 0 | 19,7% |
| 2026-03 | 31 | 166,6 | 120,6 | 228,5 | 0 | 15,5% |
| 2026-04 | 30 | 165,4 | 111,2 | 209,6 | 0 | 14,5% |
| 2026-05 | 31 | 169,8 | 127,3 | 220,1 | 0 | 13,6% |
| 2026-06 | 30 | 148,4 | 106,2 | 201,5 | 0 | 17,9% |
| 2026-07 | 31 | 160,2 | 136,9 | 181,8 | 0 | 13,5% |
| 2026-08 | 31 | 167,2 | 83,1 | 222,8 | 0 | 15,5% |
Median by duration
| Month | 1h | 2h | 4h |
|---|
| 2025-10 | 192,7 | 173,8 | 141,7 |
| 2025-11 | 129,8 | 109,5 | 82,3 |
| 2025-12 | 71,5 | 66,3 | 57,0 |
| 2026-01 | 113,5 | 100,7 | 86,8 |
| 2026-02 | 104,9 | 100,8 | 90,8 |
| 2026-03 | 180,2 | 166,6 | 151,7 |
| 2026-04 | 182,7 | 165,4 | 148,5 |
| 2026-05 | 182,6 | 169,8 | 158,7 |
| 2026-06 | 160,8 | 148,4 | 134,2 |
| 2026-07 | 168,4 | 160,2 | 143,0 |
| 2026-08 | 177,2 | 167,2 | 151,3 |
GR · EUR/MWh delivered
Figures are in EUR, the currency in which the zone publishes its price. Not comparable across zones without conversion — the same rule as for forecast error.
Before network tariffs. We do not have this zone's regulated tariffs, so the margin is before them. We do not assume them.
Wear threshold: 17,4 EUR/MWh ·
efficiency 0.85
2-hour battery
| Month | Days | Median | P10 | P90 | Days below threshold | Top 10% of days |
|---|
| 2025-10 | 31 | 190,3 | 119,8 | 257,5 | 0 | 20,5% |
| 2025-11 | 30 | 141,0 | 52,3 | 221,0 | 0 | 20,5% |
| 2025-12 | 31 | 79,8 | 30,7 | 145,1 | 0 | 22,7% |
| 2026-01 | 31 | 73,2 | 38,3 | 192,1 | 0 | 25,2% |
| 2026-02 | 28 | 110,3 | 66,1 | 144,9 | 0 | 15,8% |
| 2026-03 | 31 | 164,6 | 140,0 | 223,6 | 0 | 13,5% |
| 2026-04 | 30 | 167,6 | 110,7 | 201,6 | 0 | 13,4% |
| 2026-05 | 31 | 167,7 | 123,6 | 229,1 | 0 | 14,2% |
| 2026-06 | 30 | 164,4 | 134,6 | 202,0 | 0 | 17,7% |
| 2026-07 | 31 | 164,1 | 142,2 | 188,0 | 0 | 13,4% |
| 2026-08 | 31 | 182,7 | 120,4 | 260,3 | 0 | 15,0% |
Median by duration
| Month | 1h | 2h | 4h |
|---|
| 2025-10 | 209,7 | 190,3 | 154,4 |
| 2025-11 | 147,1 | 141,0 | 122,6 |
| 2025-12 | 90,5 | 79,8 | 60,8 |
| 2026-01 | 97,5 | 73,2 | 55,6 |
| 2026-02 | 114,3 | 110,3 | 102,3 |
| 2026-03 | 180,2 | 164,6 | 150,2 |
| 2026-04 | 182,3 | 167,6 | 153,1 |
| 2026-05 | 173,0 | 167,7 | 155,7 |
| 2026-06 | 170,4 | 164,4 | 147,1 |
| 2026-07 | 170,6 | 164,1 | 151,0 |
| 2026-08 | 196,9 | 182,7 | 168,2 |
HU · EUR/MWh delivered
Figures are in EUR, the currency in which the zone publishes its price. Not comparable across zones without conversion — the same rule as for forecast error.
Before network tariffs. We do not have this zone's regulated tariffs, so the margin is before them. We do not assume them.
Wear threshold: 17,4 EUR/MWh ·
efficiency 0.85
2-hour battery
| Month | Days | Median | P10 | P90 | Days below threshold | Top 10% of days |
|---|
| 2025-10 | 31 | 163,9 | 99,9 | 268,5 | 0 | 20,3% |
| 2025-11 | 30 | 88,5 | 37,8 | 192,6 | 0 | 22,8% |
| 2025-12 | 31 | 56,0 | 26,7 | 118,7 | 0 | 26,9% |
| 2026-01 | 31 | 100,8 | 27,3 | 254,8 | 0 | 25,2% |
| 2026-02 | 28 | 62,3 | 29,2 | 121,4 | 0 | 24,2% |
| 2026-03 | 31 | 201,9 | 138,6 | 274,4 | 0 | 13,8% |
| 2026-04 | 30 | 214,5 | 137,2 | 387,5 | 0 | 22,9% |
| 2026-05 | 31 | 216,1 | 137,8 | 305,2 | 0 | 23,9% |
| 2026-06 | 30 | 216,9 | 108,8 | 522,5 | 0 | 26,2% |
| 2026-07 | 31 | 164,5 | 136,7 | 209,0 | 0 | 19,8% |
| 2026-08 | 31 | 182,8 | 67,7 | 269,0 | 0 | 17,7% |
Median by duration
| Month | 1h | 2h | 4h |
|---|
| 2025-10 | 170,0 | 163,9 | 138,0 |
| 2025-11 | 105,7 | 88,5 | 73,1 |
| 2025-12 | 66,8 | 56,0 | 48,2 |
| 2026-01 | 113,1 | 100,8 | 82,5 |
| 2026-02 | 70,4 | 62,3 | 52,0 |
| 2026-03 | 234,7 | 201,9 | 165,6 |
| 2026-04 | 241,7 | 214,5 | 183,1 |
| 2026-05 | 231,5 | 216,1 | 191,4 |
| 2026-06 | 235,5 | 216,9 | 184,2 |
| 2026-07 | 175,4 | 164,5 | 147,4 |
| 2026-08 | 191,9 | 182,8 | 172,4 |
How much of the price solar captures
Value factor = the price captured by the solar production shape ÷ the all-hours average price of the month. Below 1.00 it measures cannibalisation: the plant produces when everyone does. The production shape is a proxy from the zone's ENTSO-E solar forecast, not any particular plant — the figure is scale-invariant, so it depends on shape only. A market statistic, not our performance. Being a unitless ratio it is comparable across zones — but only on the same months.
| Month | RO | BG | GR | HU |
|---|
| 2024-07 | — | 0,78 | — | — |
| 2024-08 | — | 0,79 | 0,69 | 0,76 |
| 2024-09 | — | 0,74 | 0,67 | 0,72 |
| 2024-10 | — | 0,74 | 0,59 | 0,78 |
| 2024-11 | — | 0,82 | 0,75 | 0,89 |
| 2024-12 | — | 1,05 | 0,93 | 0,97 |
| 2025-01 | 0,95 | 0,97 | 0,85 | 0,90 |
| 2025-02 | 0,84 | 0,85 | 0,82 | 0,81 |
| 2025-03 | 0,54 | 0,54 | 0,50 | 0,60 |
| 2025-04 | 0,49 | 0,53 | 0,47 | 0,45 |
| 2025-05 | 0,51 | 0,57 | 0,46 | 0,41 |
| 2025-06 | 0,49 | 0,49 | 0,50 | 0,48 |
| 2025-07 | 0,71 | 0,69 | 0,68 | 0,74 |
| 2025-08 | 0,46 | 0,41 | 0,38 | 0,54 |
| 2025-09 | 0,54 | 0,48 | 0,50 | 0,67 |
| 2025-10 | 0,74 | 0,74 | 0,58 | 0,82 |
| 2025-11 | 0,85 | 0,88 | 0,68 | 0,90 |
| 2025-12 | 0,98 | 0,99 | 0,83 | 0,97 |
| 2026-01 | 1,01 | 1,02 | 0,82 | 1,03 |
| 2026-02 | 0,67 | 0,68 | 0,45 | 0,82 |
| 2026-03 | 0,45 | 0,45 | 0,40 | 0,52 |
| 2026-04 | 0,44 | 0,36 | 0,24 | 0,30 |
| 2026-05 | 0,50 | 0,46 | 0,28 | 0,40 |
| 2026-06 | 0,59 | 0,54 | 0,41 | 0,62 |
| 2026-07 | 0,59 | 0,58 | 0,53 | 0,63 |
| 2026-08 | 0,66 | 0,64 | 0,54 | 0,68 |
Common window — 20 months present in every zone (2025-01 … 2026-08), mean value factor over them: RO 0,651, BG 0,643, GR 0,546, HU 0,665. Zones are compared only on these months: on each zone's full history, a zone with different months in its sample comes out different without anything having changed.
Season matters more than market. Within one zone, the gap between the best and the worst month is several times the gap between zones on the same month. An annual average hides exactly that.
What is NOT deducted
- Asset availability. Maintenance, slow balancing charges, thermal derating. A real battery is not available in every quarter-hour of every day.
- Cycle budget. The manufacturer's warranty caps cycles per year. This figure assumes you can cycle on every economically worthwhile day — which may exceed what the warranty allows.
- Auxiliary consumption. HVAC and the management system draw from the grid, typically 1–3% of throughput.
- Wear. The margin is before cycle cost. The threshold is shown separately in every table, so you can compare it yourself.
All four belong to the asset operator and all four only subtract. The figure above is what the market offered, not what anyone collects.
How we publish
- Cadence: monthly, on the first working day, for the closed month. A month in progress is never published — a partial one looks complete and can no longer be corrected without breaking the rule below.
- No retroactive editing. A published month does not change. If a price is revised, a new row appears with a reason, above the old one.
- All live zones, always — including the worst-looking one.
- Parameters are frozen and printed in every table: efficiency, wear threshold, tariffs, storage exemption. Changing them is an editorial change and is announced; it does not slip in through a recomputation.
- The value factor (from 4 Sep 2026) follows the same rules: complete months, frozen once, all zones. The production shape is a proxy from the ENTSO-E solar forecast, stated on the page; the mean is given only on months common to all zones.
Rule written on 27 August 2026, before the first bad month.