hermes-skills/smart-home/smart-home-automation/references/ha-energy-analysis.md

HA Energy/Power Analysis Methodology

How to diagnose unexpected power consumption (e.g. nighttime grid draw) using HA history data. Based on a session diagnosing ~200W nighttime grid import caused by a heat pump water heating cycle.

Sensor Inventory (This Homelab)

Grid / Net Power

Entity	Name	Notes
sensor.evcc_grid_power	Leistung Netz	EVCC aggregate grid power (W). Positive = import.
sensor.netzfluss_saldo	Tibber Pulse Netzfluss Saldo	Tibber Pulse grid balance (W). Negative = export. Higher resolution than EVCC.
sensor.stromverbrauch_haus_netto	Stromverbrauch Haus netto	Net house power consumption (W)

Home / Load

Entity	Name	Notes
sensor.evcc_home_power	Leistung Heim	Total home consumption (W)
sensor.stromverbrauch_rest	Stromverbrauch "Rest"	Unknown/rest consumption

PV

Entity	Name	Notes
sensor.evcc_pv_power	Leistung PV	Aggregate PV power (W)
sensor.hm_1500_power	HM-1500 Power	Hoymiles HM-1500 via OpenDTU/MQTT
sensor.schuppen_string_1_power	Schuppen 1 Power	Hoymiles Schuppen 1
sensor.schuppen_2_power	Schuppen 2 Power	Hoymilles Schuppen 2

Batteries

Entity	Name	Notes
sensor.evcc_battery_power	Leistung Batterie	EVCC aggregate battery (W). Positive = discharging.
sensor.evcc_battery_soc	Batterie Ladezustand	EVCC aggregate SOC (%)
sensor.sn_3007105790_battery_power_discharge_total	SMA Battery Discharge	SMA SunnyBoyStorage discharge (W)
sensor.sn_3007105790_battery_power_charge_total	SMA Battery Charge	SMA SunnyBoyStorage charge (W)
sensor.sn_3007105790_battery_soc_total	SMA Battery SOC	SMA SunnyBoyStorage SOC (%)
sensor.marstek_venus_modbus_batterieleistung	Marstek Batterieleistung	Marstek Venus (W). Negative = discharging.
sensor.marstek_venus_modbus_ac_leistung	Marstek AC-Leistung	Marstek AC output (W)
sensor.marstek_venus_modbus_batterie_ladezustand	Marstek SoC	Marstek Venus SOC (%)
sensor.marstek_target_power	Marstek Target Power	EVCC/setpoint target for Marstek (W)
sensor.sma_target_power	SMA Target Power	EVCC/setpoint target for SMA (W)

Large Consumers (Individual)

Entity	Name	Notes
sensor.shellypro3em_08f9e0e98b9c_total_active_power	Wärmepumpe Total	Heat pump total active power (W). Major consumer — up to 5.4kW.
sensor.strommessung_sauna_total_active_power	Sauna Total	Sauna total active power (W)
sensor.cu401b_s_verdichterleistung	CU401B Verdichterleistung	Heat pump compressor power (kW)
sensor.cu401b_s_verdichtermodulation	CU401B Verdichtermodulation	Heat pump compressor modulation (%)
sensor.cu401b_s_kompressorphase	CU401B Kompressorphase	Compressor phase: off/preparing/heating/pause
sensor.cu401b_s_ww_speichertemperatur	WW-Speichertemperatur	Hot water tank temp (°C). Target: 46°C, Hysteresis: 4K
sensor.ev_charger_schon_leistung_ladestation	EV Charger Leistung	SMA EV Charger station power (W)
sensor.evcc_wallbox_charge_power	Wallbox Ladeleistung	EVCC wallbox charge power (kW)
sensor.trockner_device_power	Trockner Power	Dryer power (W)
sensor.samsung_qn90aa_65_tv_power	Samsung TV Power	TV power (W)

EVCC Config / Tariff

Entity	Name	Notes
number.evcc_residual_power	Restleistung	EVCC residual power target (W). Default 100W.
sensor.evcc_tariff_grid	Kosten Netz	Current grid price (€/kWh)
binary_sensor.evcc_battery_grid_charge_active	Hausbatterie Netzladen	Whether battery is charging from grid

Heat Pump Config (ViCare / CU401B S)

Entity	Name	Notes
climate.vicare_heating	CU401B S Heizung	Climate entity. Presets: comfort/eco/home/sleep
number.cu401b_s_ww_temperatur	WW-Temperatur	WW target temp (°C). Currently 46.
number.cu401b_s_ww_hystereseschalter_ein	WW-Hysterese ein	WW hysteresis ON (K). Currently 4.
number.cu401b_s_ww_hystereseschalter_aus	WW-Hysterese aus	WW hysteresis OFF (K). Currently 4.
automation.komfort_heizung	Komfort Heizung	Automation controlling heating comfort mode

Analysis Workflow

1. Confirm the anomaly: Query sensor.evcc_grid_power history for the suspected time window. Summarize in 30-min buckets to see the pattern. Important: Ask the user for approximate time — they may point to a different window than the first obvious spike. In one session, the first analysis found a 02:47 heat pump spike, but the user clarified the issue was at 04:30+, revealing a second smaller spike that was initially overlooked.

2. Decompose the power equation: At any moment: grid = home - pv - battery_discharge + battery_charge. Query all four simultaneously to see which component is causing the imbalance.

3. Check battery SOC trajectory: If batteries drain to low SOC during the night, they can't cover the remaining demand → grid import kicks in. Plot SOC over time for both batteries.

4. Identify the triggering consumer: Query individual large-consumer sensors (heat pump, sauna, EV charger, dryer) for the same time window. Look for spikes or sustained elevated consumption.

5. Correlate with heat pump phases: The cu401b_s_kompressorphase and cu401b_s_verdichtermodulation entities show exactly when the compressor starts, what phase it's in, and how hard it's working. The ww_speichertemperatur shows whether it's a hot-water heating cycle (temp rising toward target).

6. Check EVCC control targets: marstek_target_power and sma_target_power show what EVCC is commanding the batteries to do. If these are 0, EVCC isn't actively discharging the batteries — they may be in passive mode.

7. Summarize findings: Present a timeline table showing the key events and a root-cause explanation, followed by prevention options.

Multiple Spikes Per Night (2026-07-09 Session)

In one session, two distinct grid import spikes were found in a single night:

Time	Grid Peak	Home Peak	Heat Pump	Cause
02:47	4,808 W	6,151 W	5,440 W	Heat pump WW heating (compressor 47-50% modulation, WW temp 38→47°C)
04:30	3,570 W	4,920 W	91 W (standby)	Unknown — heat pump was idle. Possibly a second WW cycle or another consumer not covered by monitored sensors.

Lesson: Don't assume the first spike is the only one. Query the full 02:00–07:00 window and look for ALL grid import periods >100W. The 04:30 spike showed home power at 4,920W but the heat pump was only drawing 91W — the 4,800W delta came from an unmonitored consumer. Future analysis should query ALL available power sensors (including sensor.stromverbrauch_haus_netto which aggregates differently from evcc_home_power) and consider unmonitored circuits.

Prevention Strategies for Nighttime Grid Import

Heat Pump WW Timing

The most impactful fix: shift hot water preparation to daytime PV hours.

• ViCare schedule: Set WW heating to only occur between 10:00–15:00 (main PV production window).
• Increase hysteresis: Change ww_hystereseschalter_ein from 4K to 6K → starts later, fewer cycles.
• Lower WW target: Reduce ww_temperatur from 46°C to 43°C → less energy per cycle.

Battery SOC Management

Ensure batteries start the night at 100%:

• EVCC priority SOC: Ensure evcc_priority_soc is set appropriately so batteries reserve enough for overnight.
• Force charge before sunset: If PV forecast predicts low production, trigger battery charging from PV surplus in late afternoon.
• Marstek discharge limit: number.marstek_venus_modbus_entladeleistung_einstellen controls max discharge rate. Lowering it extends battery runtime but may not fully cover peaks.

Combination Approach (Recommended)

Both WW timing AND battery management together provide the most robust solution.

EVCC-Side Battery Discharge Diagnosis

When the question shifts from "what consumed the power?" to "why didn't the battery cover the gap?", the EVCC api/state endpoint provides the answer. This is a different diagnostic axis from the consumption-side analysis above.

Key Fields in curl -s http://10.0.30.10:7070/api/state

Field	Path	Meaning
Controllable	battery.devices[].controllable	false = EVCC reads SoC/power but cannot command discharge
Discharge control	batteryDischargeControl	false = passive monitoring, no active discharge management
Residual power	residualPower	Watts EVCC tolerates from grid before reacting (default 100)
Battery mode	batteryMode	unknown = no active mode set
Per-battery power	battery.devices[].power	Current output (W) — compare to home power
Per-battery SOC	battery.devices[].soc	High SOC + low output = battery is limited, not empty

Diagnosis Flow

1. Check controllable — if false, EVCC cannot increase discharge. The battery's own internal limit is the bottleneck.
2. Check residualPower — if >0, EVCC deliberately allows that much grid import as baseline.
3. Compare battery output to home power — if battery output << home power and SOC is high, the battery's internal discharge limit (not EVCC) is the constraint.
4. Verify by checking spike behavior — if the battery briefly delivered much more during a spike (e.g. Marstek hit 1,437W during heat pump cycle but settled to ~650W steady-state), that confirms an internal limiter, not a capacity issue.

Case Study: Marstek Venus Not Covering 200W Gap (2026-07-10)

Symptom: ~200W continuous grid import 03:00–04:00 despite Marstek SoC at 73%.

Initial hypothesis (INCOMPLETE): EVCC controllable: false + residualPower: 100 + Marstek internal discharge limit ≈ 650W.

Actual root cause: The HA automation "Marstek Kaskaden-Steuerung (Modbus)" (automation.marstek_modbus_steuerung) controls the Marstek, NOT EVCC. EVCC sees controllable: false because it's only a passive observer. The automation has a feedback-loop bug in its echter_bedarf formula:

# BUG: uses setpoint (number.*_einstellen) instead of measured (sensor.*)
echter_bedarf: "{{ power_home - production + marstek_current_discharge - marstek_current_power }}"
# marstek_current_discharge = states('number.marstek_venus_modbus_entladeleistung_einstellen')  ← SETPOINT

This causes the discharge setpoint to spiral: 0 → 870 → 1740 → 2500 (capped) within 3 cycles (6 min). The Marstek's anti_feed mode then throttles actual output to ~650W (preventing grid export from the oversized command). The ~200W gap is the difference between what the automation commands (2500W) and what the Marstek actually delivers after anti_feed throttling (~650W), versus what the house needs (~870W).

Evidence: During the 02:43–02:57 heat pump spike, Marstek delivered up to 1,437W (proving capacity exists), but settled back to ~650W afterward — consistent with the automation ramping the setpoint up and anti_feed throttling back.

Fix: Replace setpoint variables with measured AC power in the automation:

# FIXED:
marstek_actual_ac: "{{ states('sensor.marstek_venus_modbus_ac_leistung') | float(0) }}"
echter_bedarf: "{{ power_home - production - marstek_actual_ac }}"

Result: echter_bedarf = 870 - 0 - 650 = 220W → new setpoint = 650 + 220 = 870W. Stable convergence.

See references/marstek-cascade-automation.md for the full automation YAML and analysis.

Query Templates

See references/ha-browser-console-access.md for the browser-console technique used to execute these queries when no local API token is available.

Summary query (all sensors, 30-min buckets)

// Adapt entity list and time range as needed
const entities = 'sensor.evcc_grid_power,sensor.evcc_home_power,sensor.evcc_battery_power,sensor.evcc_pv_power';
const url = '/api/history/period/2026-07-09T03:00:00?filter_entity_id=' + entities +
            '&end_time=2026-07-09T06:00:00&minimal_response';

Individual consumer spike detection

// Filter history records where power > threshold
const spikes = hist.filter(h => parseFloat(h.state) > 100).map(h => ({
  t: h.last_changed.substring(11, 16),
  v: parseFloat(h.state)
}));