Home energy storage with solar PV: when it makes sense and the rules
Updated: 06/10/2026 · 7 min read · Ozeplan editorial teamUnder net-billing, energy fed into the grid is valued at the market price, and for prosumers who started feeding in from 1 July 2024 energy fed in during a period with a negative price is worth 0 PLN. A battery lets you use more of your own energy instead of selling it cheaply. Storage up to 30 kWh needs no building permit or notification. From 20 October 2026 you can apply in the "Przydomowe magazyny energii, part 2" programme: up to 30% of costs, at most 800 PLN per kWh and up to 16,000 PLN for net-billing prosumers.
Why a battery under net-billing
Net-billing no longer lets you "store" energy in the grid as the old net-metering did. Surplus energy is sold at the market price, and in periods with a negative price (for prosumers since 1.07.2024) it is worth nothing. A battery shifts energy from midday to the evening, raising self-consumption. Settlement rules are explained in Net-billing.
We found no official, independent payback calculation for home batteries. It depends on your consumption profile, energy prices and subsidies, so ask the contractor for a calculation based on your data.
How to size the battery
In PME part 2 the battery capacity in Wh must be at least twice the PV peak power in W, so at least 2 kWh per kWp, and no less than 10 kWh.
The programme also requires an energy management system (EMS) and backup (island) operation during grid outages.
Storage power is not added to the micro-installation's power if neither the storage power nor the total power that can be fed into the grid exceeds the installed power of the micro-installation (Energy Law, art. 7(8d12)).
Formalities and safety
Up to 30 kWh: no building permit and no notification (Building Law amendment of 4.12.2025).
Above 30 kWh up to 300 kWh: a notification, fire-safety agreement of the documentation and notice to the State Fire Service with a plan for rescue teams.
The battery must be reported to the grid operator together with the installation data (TAURON Dystrybucja, for example, has a form for storage data).
Firefighters ask owners to tell them whether and where batteries are installed.
Subsidy: Przydomowe magazyny energii, part 2
NFOŚiGW call rules, September 2026. Applications: 20.10.2026, 09:00 – 1.10.2027, 20:00 or until funds run out.
Spending on electricity and heat storage can also be deducted under the thermal modernisation relief since 1 January 2025, except the amount covered by a grant.
Frequently asked questions
Does a home battery pay off under net-billing?
A battery raises self-consumption, because under net-billing surplus energy is sold at the market price and in negative-price periods (for prosumers since 1.07.2024) is worth 0 PLN. Payback depends on consumption and prices; there is no official figure.
What battery size for a 10 kWp system?
To use PME part 2 the battery needs at least 2 kWh per kWp, so at least 20 kWh for 10 kWp, plus an EMS and backup operation.
How much is the home battery subsidy in 2026?
In PME part 2: up to 30% of costs, at most 800 PLN per kWh, up to 16,000 PLN for net-billing prosumers and 8,000 PLN for net-metering. Applications from 20.10.2026.
Does a home battery need a building notification?
Not up to 30 kWh. From 30 to 300 kWh you need a notification with a fire-safety agreement and notice to the fire service.
Sources
Regulations and programmes checked on the update date.
See installers who travel to your town: range, availability, projects and checked certificates.
Related guides
This guide is for information only. Regulations and programme terms change, so check the current sources before deciding.