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EvCompass

Home battery calculator

Estimate how a home battery could affect electricity costs, PV self-consumption and simple payback under Polish tariffs and net-billing prices.

Electric car use

Choose a car, or enter energy use manually

A selected catalogue car fills its published consumption when available. Otherwise, enter an indicative value yourself.

km/year

Annual kilometres are spread evenly across the twelve monthly steps.

kWh/100 km

The default is an editable estimate; catalogue consumption is used when available.

%

Share of the car's annual electricity charged at this home.

Home energy system

kWh/year

Default uses the latest GUS household average; detached homes may use more.

kWp

PVGIS Warsaw reference: south-facing, 35° tilt, 14% system losses.

kWh

Other battery sizes need your own installed-price quote; the 10 kWh examples are not scaled.

%

Editable share of PV output used immediately, before the battery.

%

Editable share of household use that can be served by stored energy.

Installed battery cost

Public vendor examples for a 10 kWh system, gross installed: PLN 21,000–35,000; not a national average.

PLN

Gross installed cost in PLN.

PLN

Gross installed cost in PLN.

Potential PME2 grant

Result

Illustrative monthly model · source data checked 2026-10-19

Estimated annual savings
PLN 2,654
Simple payback range
7.9–13.2 years
Added PV used from battery
2,652 kWh
EV-attributed share of savings
PLN 1,752
Monthly PV output, battery use, exports and estimated savings
MonthPV outputPV stored and usedPV exportsSavings
January165 kWh104 kWh0 kWhPLN 151
February249 kWh174 kWh0 kWhPLN 183
March446 kWh279 kWh74 kWhPLN 275
April595 kWh270 kWh235 kWhPLN 288
May655 kWh279 kWh283 kWhPLN 275
June676 kWh270 kWh316 kWhPLN 236
July666 kWh279 kWh294 kWhPLN 248
August631 kWh279 kWh258 kWhPLN 236
September519 kWh270 kWh159 kWhPLN 210
October357 kWh265 kWh0 kWhPLN 219
November166 kWh105 kWh0 kWhPLN 170
December126 kWh79 kWh0 kWhPLN 162

How to read this estimate

This is a flat-load monthly estimate, not a measured household profile or an optimizer. It assumes one battery cycle per day, 90% round-trip efficiency, PV-first charging and an indicative day-rate value for load served by the battery. The PGE tariff rates are an indicative variable-charge reconstruction; fixed fees and account-specific deposit expiry are excluded.

Smallest modelled capacity reaching 90% of the best annual benefit: 10 kWh.

Estimated household-only annual savings: PLN 902.

Official status checked 2026-10-19: PME2 (nabór trwa od 20.10.2026 do 01.10.2027). The form is available only from 2026-10-20 09:00 Warsaw time.

The published storage component is up to 30% of eligible cost from 2025-11-01, capped at PLN 800/kWh and PLN 16,000 for net-billing or PLN 8,000 for net-metering. A separate EU storage-and-inverter bonus may add up to PLN 2,000; the minimum is 10 kWh and capacity must be at least 2 times PV peak power.

PME1 applications closed 2026-06-19; assessment had reached applications from 2026-10-16. Mój Prąd 6 applications closed 2025-08-29.

No PME2 estimate is shown until the conditions are confirmed and the storage is at least 10 kWh and twice the PV peak power.

The termomodernisation relief may allow an owner or co-owner to deduct up to PLN 53,000 per taxpayer with an active VAT invoice; finish the project within 3 years and exclude grant-refunded costs. It is not subtracted from payback.

Grid-connection reporting depends on battery power and the property's connection capacity. The storage register applies above 50 kW; building and fire duties depend on location and size (outside-building installations up to 30 kWh have no building notice or permit requirement).

Sources checked 2026-10-19; GUS household default is the 2025 figure (1,832.8 kWh/year), replacing the 2024 design value of 1,831.8.

Source names, check dates and caveats
  • EvCompass estimate — 2026-10-19: Default car profile: 15000 km/year, 18 kWh/100 km, 70% home charging. This is an editable default profile; 18 kWh/100 km is used only when no selected car has suitable published consumption data.
  • EvCompass estimate — 2026-10-19: Load-shape defaults: 30% of PV used directly, 60% of household use outside PV hours; load is spread evenly across the year, with 1 battery cycle per day. These editable illustrative values are not measured: household load is spread evenly through the year, the battery is limited to one cycle per day, and home EV charging is assumed outside PV hours.
  • EvCompass default scenario — 2026-10-19: Default PV reference: 5 kWp at Warsaw. Annual yield comes from the dated PVGIS source; 5 kWp is an editable default.

Compare home charging costs with the home-charging calculator

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