Arbitrage Tracker (gw-pi2, Sezibwa)

Cumulative record of the TOU battery arbitrage on gw-pi2 (Sezibwa). Each night the inverter discharges the battery during a peak-tariff window and recharges it from the grid at the off-peak rate from 00:00. Daily progress goes to the Element business room; this page is the running record. It is rebuilt from the OpenEMS backend by scripts/arbitrage_tracker.py in the nfe-modbus-energy-logger repo.

Settings and why they were chosen: Arbitrage Window and Thresholds (decision record).

Last updated: 2026-10-2627 06:4932 EAT.

Totals

Measure	Value
Nights armed	027
Energy shifted to peak	0.0116.2 kWh
Estimated net saving	021,972 UGX
Average per armed night	4.30 kWh, 814 UGX
Projected per month at that rate	24,413 UGX

Night by night

data(edgeoffline)

Night	Config	Window	Start	SoC start	SoC end	Shifted (kWh)	Peak (kW)	Lowest pack (V)	Saving (UGX)	Recharge 00-06 (kWh)	Notes
2026-09-26	v12	22:00-23:59	22:03	78%	48%	3.08	6.1	50.96	582	5.9	nofirst dataarmed (edge offline)night
2026-09-27	v13	off				0			0	4.5	nodisarmed: dataSoC (edge65% offline)after the 27 Sep overload outage
2026-09-28	v14	21:30-23:30	21:33	87%	64%	2.28	4.6	51.45	432	4.1	nowindow datamoved (edgeto offline)21:30-23:30
2026-09-29	v15	off				0			0	5.5	nodisarmed: dataSoC (edge61% offline)after the 05:15-07:51 grid outage
2026-09-30	v17	21:00-23:00	21:03	87%	60%	2.75	6.3	50.94	519	4.5	window 21:00-23:00, no datamore (edgemanual offline)disarms
2026-10-01	v18	off				0			0	5.7	noskipped: datatwo (edgeoutages offline)left SoC at 51% before the window
2026-10-02	v18	off				0			0	1.7	nostill datadisarmed (edgere-arm offline)missed)
2026-10-03	v19	21:00-23:00	21:03	64%	38%	2.64	4.4	51.10	499	7.0	nore-armed datawith (edgethe offline)v17 profile
2026-10-04	v19	21:00-23:00	21:03	84%	63%	2.17	2.2	52.17	410	4.3	no data (edge offline)
2026-10-05	v21	18:00-23:59	19:22	15%	9%	0.08	1.9	49.32	15	10.8	nodriver datarules live: start at 30% or above, floor 15%; 0.9 kWh of the discharge was during an outage (edgebackup, offline)not counted)
2026-10-06	v21	18:00-23:59	18:04	89%	25%	5.04	4.0	51.14	953	8.4	no1.5 datakWh of the discharge was during an outage (edgebackup, offline)not counted)
2026-10-07	v21	18:00-23:59	18:04	89%	25%	6.56	5.0	51.00	1,239	8.3	no data (edge offline)
2026-10-08	v21	18:00-23:59	18:04	89%	21%	6.88	5.5	50.22	1,300	8.7	no data (edge offline)
2026-10-09	v21	18:00-23:59	18:04	79%	28%	5.18	4.3	50.88	980	8.0	no data (edge offline)
2026-10-10	v21	18:00-23:59	18:04	65%	15%	4.96	4.1	51.10	938	9.4	no data (edge offline)
2026-10-11	v21	18:00-23:59	18:04	54%	15%	3.59	4.3	50.26	679	9.2	no data (edge offline)
2026-10-12	v21	18:00-23:59	18:00	77%	15%	6.12	4.4	50.52	1,157	9.0	no data (edge offline)
2026-10-13	v21	18:00-23:59	18:03	89%	15%	7.51	5.1	50.34	1,419	9.3	no data (edge offline)
2026-10-14	v21	18:00-23:59	18:04	89%	23%	6.76	4.1	50.82	1,277	8.5	no data (edge offline)
2026-10-15	v21	18:00-23:59	18:04	89%	20%	6.97	4.1	50.62	1,317	7.3	no data (edge offline)
2026-10-16	v21	18:00-23:59	18:04	92%	15%	7.97	4.1	50.28	1,507	9.6	no data (edge offline)
2026-10-17	v21	18:00-23:59	18:04	55%	15%	4.16	4.1	50.37	786	9.6	no data (edge offline)
2026-10-18	v21	18:00-23:59	18:04	80%	15%	1.47	5.7	50.54	278	10.7	no5.9 datakWh of the discharge was during an outage (edgebackup, offline)not counted)
2026-10-19	v21	18:00-23:59	18:04	75%	15%	5.64	4.1	50.27	1,067	10.2	no0.2 datakWh of the discharge was during an outage (edgebackup, offline)not counted)
2026-10-20	v21	18:00-23:59	18:04	40%	15%	2.50	4.2	50.68	473	9.6	no data (edge offline)
2026-10-21	v21	18:00-23:59	18:05	87%	15%	4.90	4.3	50.26	926	7.9	no1.1 datakWh of the discharge was during an outage (edgebackup, offline)not counted)
2026-10-22	v21	18:00-23:59	18:04	36%	9%	2.33	3.3	49.43	440	10.3	no0.9 datakWh of the discharge was during an outage (edgebackup, offline)not counted)
2026-10-23	v21	18:00-23:59	18:10	90%	15%	1.06	4.2	0.00	200	2.6	no data (edge offline)
2026-10-24	v21	18:00-23:59	18:05	40%	15%	0.65	3.7	0.00	123	2.1	no data (edge offline)
2026-10-25	v21	18:00-23:59	18:04	89%	19%	7.12	4.3	50.76	1,346	8.9
2026-10-26	v21	18:00-23:59	18:05	82%	22%	5.87	no5.1	50.42	1,109	8.7

Outages and reliability

Every grid outage, with how the battery carried it and how much of the reserve that night's arbitrage had already used. This is the record for judging what the deeper discharge costs in backup.

No

outagesrecordedsince

Measure	Value
Outages	42 (62.8 h)
Outages where the firstsite armedwent night. dark	5
Outages that started after an arbitrage night, before the recharge	0
Of those, site went dark	0

Date	Start	End	Duration	SoC at start	Lowest SoC	Lowest pack (V)	Battery supplied (kWh)	Site dark	Arbitrage use before (kWh)	Notes
2026-10-01	10:45	14:12	3h27	93%	60%	52.16	3.4	no
2026-10-01	20:20	20:42	0h22	56%	52%	51.92	0.5	no
2026-10-03	15:10	16:49	1h39	90%	66%	52.10	2.5	no
2026-10-04	16:35	16:52	0h17	90%	87%	52.60	0.3	no
2026-10-05	06:40	09:27	2h47	96%	68%	52.07	3.0	no
2026-10-05	10:35	13:44	3h09	66%	37%	51.70	2.9	no
2026-10-05	13:50	14:42	0h52	37%	31%	51.91	0.5	no
2026-10-05	15:25	17:17	1h52	30%	15%	50.91	1.6	no
2026-10-05	19:25	20:55	1h30	15%	9%	49.32	1.0	yes, 48 min no data
2026-10-06	19:20	20:06	0h46	81%	64%	52.00	1.7	no
2026-10-09	16:50	17:55	1h05	90%	79%	52.62	1.1	no
2026-10-10	10:45	10:47	0h02	93%	93%	52.92	0.0	no
2026-10-10	12:30	12:54	0h24	92%	89%	52.80	0.3	no
2026-10-10	15:15	17:39	2h24	88%	65%	52.32	2.4	no
2026-10-11	02:15	08:20	6h05	100%	60%	52.28	4.0	no	0.0
2026-10-12	17:20	18:04	0h44	89%	77%	51.99	1.3	no
2026-10-16	03:45	05:03	1h18	98%	89%	52.90	0.9	no
2026-10-17	03:39	03:43	0h04	98%	98%	53.05	0.0	no
2026-10-17	03:50	07:03	3h13	98%	74%	52.80	2.4	no
2026-10-17	13:50	15:15	1h25	70%	57%	52.17	1.3	no
2026-10-18	03:49	03:52	0h03	98%	98%	53.05	0.0	no
2026-10-18	12:35	13:34	0h59	92%	83%	52.53	1.0	no
2026-10-18	19:25	22:38	3h13	67%	15%	50.54	6.0	no
2026-10-19	02:20	03:03	0h43	100%	94%	52.90	0.5	no
2026-10-19	13:50	15:43	1h53	92%	76%	52.49	1.8	no
2026-10-19	19:30	19:40	0h10	60%	58%	52.01	0.2	no
2026-10-20	04:25	05:24	0h59	98%	91%	52.90	0.7	no
2026-10-20	05:50	09:30	3h40	100%	61%	51.92	4.3	no
2026-10-20	09:35	09:36	0h01	61%		52.52	0.0	no
2026-10-20	09:40	11:07	1h27	60%	44%	51.70	1.6	no
2026-10-21	12:50	12:51	0h01	93%		52.95	0.0	no
2026-10-21	12:55	13:10	0h15	92%	90%	52.77	0.2	no
2026-10-21	20:45	22:59	2h14	56%	16%	50.26	2.9	yes, 38 min no data
2026-10-22	03:40	09:37	5h57	97%	41%	52.50	1.7	yes, 234 min no data
2026-10-22	19:33	20:00	0h27	15%	13%	50.16	0.8	no
2026-10-22	20:05	20:12	0h07	13%	12%	50.18	0.0	no
2026-10-22	20:25	20:26	0h01	12%	12%	50.21	0.0	no
2026-10-22	20:30	20:34	0h04	11%	10%	49.43	0.1	yes, 0 min no data
2026-10-24	07:15	11:43	4h28	96%	60%	52.60	0.7	yes, 216 min no data
2026-10-24	12:50	14:29	1h39	59%	43%	51.83	1.7	no
2026-10-26	13:40	14:35	0h55	92%	84%	52.70	0.8	no
2026-10-27	03:45	03:50	0h05	98%	98%	53.06	0.0	no

Where to tweak

• Unused battery headroom: the battery ends the window with an average 0.4 kWh above its floor (45% before the driver rules, 15% from v21) (73 UGX a night if shifted too).
• Peak energy still bought from the grid: 1.2 kWh a night between 18:00 and midnight falls outside the window. That is the ceiling for more shifting, limited by battery size and the backup reserve.
• Voltage margin: the lowest pack voltage so far is 49.32 V against the 50.4 V disarm trigger and 48.8 V inverter cut-off.
• Spread: each shifted kWh earns about 189 UGX net (666.5 peak minus 429.7 off-peak at 90% round trip). A new quarterly tariff changes this directly.

Method

• Shifted energy: battery discharge (ess0/ActivePower > 0) integrated over the configured window, with 10 minutes added at the end for the inverter clock lag. Only minutes with the grid present count; discharge during an outage is backup, not arbitrage, and is shown in the notes.
• Saving: shifted kWh at the peak rate, minus the off-peak cost of putting that energy back at 90% round-trip efficiency. It is energy only (no service charge, VAT or battery wear).
• Recharge: battery charging between 00:00 and 06:00. It includes refilling any evening outage use, so it can exceed the shifted energy.
• Config history: ADR-016 in the microgrid-gateway repo (v12 22:00-23:59, v13 off, v14 21:30-23:30 from 28 Sep, v17 21:00-23:00 from 30 Sep, v18 off 1-2 Oct, v19 re-armed from 3 Oct, v21 from 5 Oct: 18:00-23:59 with the driver's 30% start and 15% floor).
• Outage: a minute counts as an outage when any phase of the inverter's grid-side meter (meter0) reads under 150 V or the inverter reports machine state 3 (off grid). Minutes with no data during an outage mean the edge lost power, which means the site went dark; an outage counts as dark at 5 such minutes or when SoC fell to 10% (the inverter's cut-off point seen on 24 Sep).
• Arbitrage use before an outage: the energy that night's window took from the battery (grid present), for outages that start after the window and before 06:00. It is the backup the site did not have because of arbitrage. An outage that starts inside the window is marked, because from then on the discharge is backup.