Phase 1 is a Balkonkraftwerk built around the Anker SOLIX Solarbank 4 Pro E5000 — pure bill reduction + Home Assistant tinkering, in preparation for 2026. Phase 2 is a separate, later full house system with a hybrid inverter and HV battery, delivering whole-house backup + EV charging. The two don't merge — the Solarbank stays a self-contained appliance.
Distilled 2026-07-11 from the Anker Solarbank evaluation · revised 2026-07-16 after adversarial review · household ~4,900 kWh/yr (~13 kWh/day)
01
Two phases, one house
The Solarbank is a self-contained appliance — it does not grow into Phase 2. Its long-term value carries over as data, panels, and mounting, not as hardware.
Phase 12026 · in preparation
Balkonkraftwerk (BKW)
An 800 W plug-in appliance for bill reduction and Home Assistant tinkering — nothing more.
✓ Cut the electricity bill (800 W feed-in)
✓ Home Assistant control via local Modbus TCP
✓ Smart-meter consumption data
~ Panels + mounting reusable in Phase 2 — with caveats (dedicated MPPT · same surface)
✕ Whole-house blackout backup
✕ Meaningful EV solar charging
Phase 2Later — house system
Full house PV system
Hybrid inverter, HV battery, electrician, and full administrative process — a regular PV installation, not a BKW.
✓ Whole-house blackout backup (transfer switch)
✓ Wallbox surplus EV charging (~11 kW)
✓ Hybrid inverter + HV battery + PV strings
~ AC-coupled coexistence possible (two control loops, one grid point — verify)
✕ Reuses the Solarbank unit (stranded — proprietary)
02
Phase 1 configuration
Anker SOLIX Solarbank 4 Pro E5000 — Kleines Kraftwerk bundle incl. Smart Meter Gen 2.
5,024 Wh
Base capacity
~4.5 kWh usable
5,000 W
PV input
over 4 MPPTs
800 W
Feed-in (AC)
permanent standard mode
1,799 €
Bundle price
incl. Smart Meter Gen 2 · 2026-07, re-check at order
10,000
Cycles
vs ~6,000 SB3 Pro — calendar aging governs (~10–15 yr)
IP66
Ingress rating
outdoor-rated
2,000 Wp
Panels
4 × 500 Wp, E-W ~12° (bifacial gain ≈ nil at this tilt)
Local
HA integration
official Anker, Modbus TCP — cloud for onboarding only; zero-export locality: see checklist
Configuration note
Why standard 800 W mode
Never pay for the 2,500 W "Plugin Power 2.0" unlock — it requires Wieland + electrician + VDE commissioning and buys little. 800 W is a ceiling on the Solarbank's contribution, not an appliance threshold: loads under 800 W (fridges) are fully covered; bigger loads get the first 800 W offset with the grid topping up.
Connection: Wieland socket (required above the 960 Wp Schuko limit), installed in the same electrician visit as the Shelly Pro 3EM in the Zählerschrank. Meter roles: the Anker Smart Meter Gen 2 drives zero-export; the Shelly feeds HA and survives into Phase 2 — dashboards read the Shelly, never mix the two in one automation. Network: Solarbank + Shelly on the IoT VLAN; Modbus TCP has no auth, firewall it to the HA host.
03
Sizing & yield
Household ~4,900 kWh/yr (~13 kWh/day). Bars show generation, not realized offset — the battery is often full by early afternoon and the excess is curtailed. No expansion battery up front.
Summer yield8–10 kWh/day
Winter yield2–3 kWh/day
Daily need~13 kWh/day
2 kWp E-W generation vs household daily consumption (bars drawn at the top of each range). Summer generation approaches the daily total on paper; the realized offset is lower — see The money. Winter is supplemental.
Battery fit
Matched to base load
Of the 5 kWh base capacity, ~4.5 kWh usable covers evening and overnight base load. On gaming evenings (3 PCs) it drains in ~3–5 h and the grid tops up — fine for bill reduction, not an autonomy claim.
All-in ~2,050–2,250 € for an estimated ~510 €/yr saved — the system pays back in ~4–4.5 years. The battery increment alone does not; it's carried by the tinkering.
~2,150 €
All-in cost
1,799 € bundle + 250–450 € electrician visit
~510 €/yr
Est. savings
~1,800 kWh/yr · ~85 % self-consumed · 0.35 €/kWh
~4–4.5 yr
System payback
the number that carries the € case
~9–10 yr
Battery-only payback
the increment vs a no-battery BKW
No-battery 2 kWp BKW~2.3 yr
This system~4–4.5 yr
Battery increment alone~9–10 yr
Payback comparison, scale 0–10 yr (bars at mid-estimates). Self-consumption splits (~85 % with battery / ~60 % without) are estimates to refine during monitoring.
Eyes open
What the battery is really for
Blackout ("worth ~nothing") and EV charging ("cannot meaningfully") are already written off — the battery's ~1,250–1,300 € increment buys ~130 €/yr plus HA tinkering, smart-meter data, and tariff-arbitrage optionality. That's the deal, accepted knowingly.
Assumptions
Refine after monitoring
Generation ~1,700–1,900 kWh/yr (2 kWp E-W); electricity 0.35 €/kWh (BDEW 2026 band 0.31–0.40); ~5 % battery round-trip loss; prices re-checked at order time.
05
Regulatory limits — BKW status
VDE-AR-N 4105:2026-03 (in force 2026-03-01). BKW-privileged status requires BOTH caps simultaneously — they are independent.
800 VA
AC feed-in cap
the inverter/grid limit
2,000 Wp
DC module cap
the panel power limit — NOT dropped
Connection tier
≤ 960 Wp
Schuko OK Standard Schuko plug permitted (DIN VDE V 0126-95).
Connection tier
961–2,000 Wp
Wieland Requires Wieland / fixed connection by an Elektrofachkraft. This is our tier.
Connection tier
2,000–7,000 Wp
Not a BKW Simplified-documentation tier (form F.1.2), but a regular PV installation — no BKW privileges.
Bestandsschutz is explicit for pre-2026 installations. Registration goes through MaStR, which replaces grid-operator notification under the 2026 standard. Re-verified 2026-07 (pv-magazine, VDE, home&smart); bifacial rear-side gain does not count toward the 2,000 Wp nameplate cap.
06
Blackout coverage
✓
Decision: not part of Phase 1
German SAIDI is only ~12–15 min of outage per year; a closed fridge keeps food safe ~4 h, a full freezer 24–48 h. Nobody will re-plug appliances mid-outage — so the off-grid socket is worth ~nothing for the kitchen fridges. Doing nothing fits the actual outage profile.
Constraint
No house backfeed
The Solarbank cannot backfeed house wiring; island power exists only at its own 2,500 W off-grid socket.
Constraint
Nobody re-plugs
Household reality: no one re-wires appliances during an outage, so the blackout socket goes unused.
Constraint
400 V loads never
Hardwired 400 V stove/oven can never be backed up by any BKW-class device.
Runtime, IF anyone ever re-plugged (~4.5 kWh usable)
2 fridges (~120 W)~1.5 days
+ router + 1 PC~9 h
3 gaming PCs + fridges~3 h
+ 1 kW electric heat~1.5–2 h
Off-grid socket only, if someone manually re-plugged loads. With sun, the fridge case runs indefinitely (sun-limited).
Opportunistic option: if the unit's final position puts a garage chest freezer within clean permanent cable reach, it can live on the pass-through socket and ride through outages with zero action — verify pass-through spec first.
07
Car charging
✕
Cannot meaningfully solar-charge the Tesla
Panels wired into the Solarbank MPPTs can only exit through the 800 W tap (≈ 4 km range/h) or the unlocked 2,500 W tap (≈ 13 km/h). Once the battery is full, excess PV is curtailed.
Roadmap
Why a wallbox needs Phase 2
A wallbox connects to the house consumer unit (typically 3-phase 11 kW) and does surplus charging by watching the grid-point smart meter — it needs a real PV installation behind it.
Reference
Conversion overhead
Vacuum on off-grid outlet — 1 conversion (battery DC → inverter AC)
Drill charger — 2 conversions (DC → AC → charger DC); no external DC tap on the Solarbank
08
Process before ordering
Five steps — the only hard deadline starts at commissioning.
1
Electrician visit
Install the Shelly Pro 3EM (grid-point smart meter) + Wieland socket in the Zählerschrank — one visit.
2
Monitor 2–4 weeks
The annual total is known — this captures the load-curve shape (which drives the self-consumption estimate) and proves the fresh Shelly install before committing ~2k €.
3
Order once the checklist passes — no VAT deadline
The 0 % VAT rate (§12 Abs. 3 UStG) is open-ended (BMF FAQ, checked 2026-07); the previously assumed "December 2026 window" doesn't exist. No false urgency — let the monitoring finish.
4
Register in MaStR within 1 month of commissioning
The real deadline: late registration is an Ordnungswidrigkeit (§21 MaStRV), up to 10 €/kWp/month until corrected. MaStR replaces grid-operator notification under VDE-AR-N 4105:2026-03.
5
Notify the insurer
A 5 kWh battery is plausibly a Gefahrerhöhung for Wohngebäude-/Hausratversicherung — one call, ask for written confirmation. Undisclosed, it can taint unrelated claims.
Verify at purchase: zero-export control works fully locally (Smart Meter Gen 2 Modbus support still "coming soon"); charge/discharge write registers are actually exposed among the ~19 Modbus data points; off-grid socket pass-through + auto-switchover behavior on the SB4 Pro specifically; warranty terms captured; LFP low-temp charging + placement spec checked; panel Voc/Vmp/Imp recorded for Phase 2 string planning. Week 1 after delivery, inside the return window: measure standby draw — no published figure exists. Buy/no-buy rule: order only if fully-local zero-export is shipped or the Shelly-emulation path is proven — otherwise the no-cloud premise is void; reassess rather than fall back to cloud.
09
Phase 2 — the future house system
A separate, later project: a regular PV installation, not a BKW. AC-coupled coexistence with the Solarbank is possible — but that's two uncoordinated control loops at one grid point; verify at design time.
Phase 2 component
Hybrid inverter + HV battery
PV strings on a hybrid inverter with a high-voltage battery — the core of a whole-house system.
Phase 2 component
Backup box / transfer switch
Automatic whole-house blackout backup — a standard checkbox on house systems, impossible on any BKW.
Phase 2 component
Wallbox with surplus charging
3-phase ~11 kW wallbox doing real PV-surplus EV charging off the grid-point meter.
Phase 2 component
Electrician + admin process
Full administrative process — a regular PV installation, not a layperson BKW registration.
Carries over from Phase 1
Shelly smart meter Survives
The grid-point meter carries straight into Phase 2.
Carries over from Phase 1
Panels + mounting Caveats
Aged panels don't mix into new strings (Vmp/Imp drift) — plan a dedicated MPPT, contingent on the Phase 2 inverter. Mounting transfers only if Phase 2 uses the same surface; a 12° tent rack is not roof-rail hardware.
Carries over from Phase 1
Solarbank + BP batteries Stranded
Proprietary, sealed appliance — does not integrate; its lasting value was the data + HA experience. Vendor support can also die during Phase 1 (Anker scopes active support to the latest generation) — the unit still does its 800 W job standalone.
Bottom line: the Solarbank is a self-contained Phase 1 appliance, not a foundation for Phase 2. Its long-term value is the smart-meter data, the panels/mounting, and the Home Assistant control experience.
Units used — worked through a microwave
One microwave (~800 W), read in every unit
The same everyday appliance, seen through each unit used on this page.
800 WPower it pulls while running — exactly the Solarbank's feed-in cap, so on a sunny day the panels cover it outright.
0.16 kWhEnergy for a 12-min meal (800 W × 0.2 h) — a rounding error against the ~13 kWh/day household use.
2,000 WpMidday the array makes enough DC for ~2–3 microwaves — but the 800 W tap lets only one's worth reach the house; the rest charges the battery or is curtailed.
230 VThe single-phase mains voltage it plugs into (the oven beside it is 400 V three-phase — un-backupable).
~5.6 hNonstop microwaving from a full battery on the off-grid socket — 4.5 kWh ÷ 0.8 kW.
1 conversionBattery DC → inverter AC to run it in a blackout (a phone charger plugged into it would add a second).
WWatt — instantaneous power (PV input, feed-in tap).