Skip to content
GuideStorageBern

Sizing a PV battery storage system right (Bern)

A battery bridges the timing gap between solar production around midday and consumption in the morning and evening. The rule of thumb is roughly 1 kWh of usable capacity per installed kW of PV power, often also a factor of 1.5 (~1.5 kWh/kWp); alternatively Swissolar uses half a day's consumption, i.e. annual use divided by 730. Without measures a single-family home covers about 30% of its electricity demand itself, with a suitable battery up to 70%. Canton Bern has no general cantonal storage subsidy; only the city of Bern, through Energie Wasser Bern (ewb), subsidises storage with CHF 100 per kWh and only in combination with a PV system. This guide frames the sizing, the guide prices of CHF 600-900/kWh and the Pronovo reporting duty for owners in the Bern area.

Read guideRequest project

Contents

Short answerAt a glanceDecision pointsSequenceChecklistFAQSources

Short answer

How big should a battery storage system for my PV be?

For owners in canton Bern deciding before or shortly after a PV build whether and how large a battery makes sense - with sourced sizing rules, guide prices and the real subsidy and reporting situation.

Important

As of 2026: canton Bern has no general cantonal storage subsidy - the CHF 100/kWh from ewb/Oekofonds applies only within the city of Bern and only in combination with a PV system; the ewb application must be submitted before installation starts. A battery's economics are a scenario under high self-consumption and low feed-in remuneration, not a guaranteed return.

At a glance

Key figures: Battery storage sizing – Bern

Key figures for Battery storage sizing – Bern, updated 27 June 2026
MetricValue
Sizing rule of thumb~1.5 kWh storage per kWp PV (6 kWp -> 9 kWh)
Guide priceCHF 600-900/kWh incl. inverter & installation
Self-consumption~30% without, up to 70% with storage
City of Bern subsidy (ewb)CHF 100/kWh, city area only, PV only
Lifespan / warranty10-20+ years, 7-10 year warranty (LFP)

Decision points

What determines the right path.

Sizing by PV power: Swissolar uses kWp x 1.5 = storage capacity in kWh - a 6 kWp system thus points to about 9 kWh. An oversized battery often stays unused and worsens the economics.

Sizing by consumption: annual electricity use (kWh) / (2 x 365) yields roughly half a day's use as a sensible capacity. For economic reasons usually no more than ~1.5 kWh/kWp is recommended.

Self-consumption rate as the lever: about 30% without measures, around 50% with an optimised heat pump and e-mobility, up to 70% with a battery and up to 90% per Swissolar. SwissEnergy cites economic viability from about a 35% self-consumption rate as orientation.

Cost and lifespan: guide price CHF 600-900 per kWh including inverter and installation; lithium-ion/LFP systems with a 7-10 year product warranty and a 10-20+ year lifespan. About 80% of home storage units are LFP batteries.

Economics are a scenario, not a guaranteed return: a battery pays off mainly with a high self-used share and low feed-in remuneration. SwissEnergy cites about CHF 8,000 for 15 kWh of storage on a 12 kW system as a worked example.

Subsidies depend on location: no general cantonal storage subsidy in Bern; only within the city area does ewb/Oekofonds grant CHF 100/kWh (from 4 to 50 kWh), above that a flat CHF 5,000 - and only together with PV.

Sequence

How the project stays cleanly managed.

  1. 1

    Capture consumption profile and PV powerrecord annual electricity use in kWh and the planned or installed kWp, so both rules of thumb (1.5 kWh/kWp and annual use / 730) can be calculated.

  2. 2

    Estimate self-consumption without storageif it is already high (e.g. heat pump, EV, daytime use), the added benefit of a battery is smaller than the rule of thumb suggests.

  3. 3

    Check the economic frameweigh the self-used share against feed-in remuneration; SwissEnergy cites about a 35% self-consumption rate as an orientation threshold - a scenario, not a promised return.

  4. 4

    Clarify the subsidy situationcheck whether the building lies within the city of Bern; if so, submit the ewb storage subsidy application online and before installation starts (the approval is valid for one year from the confirmation date).

  5. 5

    Define technical featuresbackup/emergency power is a separate feature not every battery offers, and choose AC or DC coupling (ewb funds both variants).

  6. 6

    Obtain quotes on a comparable basisuse the guide price of CHF 600-900/kWh incl. inverter and installation as orientation, and watch usable capacity, warranty and lifespan.

  7. 7

    Report a retrofitted batteryif storage is added after the PV system, it must be reported to Pronovo by email to info@pronovo.ch - with project number, capacity (kWh), technology, make, type and commissioning date.

Checklist

Questions to settle before the quote.

  • Rules of thumb: 1.5 kWh per kWp of PV power, or half a day's consumption (annual use / 730)
  • Lifting self-consumption from ~30% without storage to up to 70% - and when this pays off
  • Subsidies in Bern: no general cantonal storage subsidy, but CHF 100/kWh via ewb within the city of Bern
  • Reporting retrofitted storage to Pronovo and backup power as a separate technical feature

FAQ

More questions: Battery storage sizing – Bern

Sources

Official sources & references.

The responsible authorities are decisive. Always verify binding details – amounts, deadlines and conditions – for your specific property against the current status of the respective authority.

Continue

Relevant pages for the next step.

For Bern, you'll find matching services, regional projects and related guides that take you forward in practical terms.

Open cantonGuide hub
Regional service

Solar Installation Bern – Planning to Commissioning

Canton Bern implemented MuKEn 2014 modularly and pursues one of Switzerland's most ambitious expansion goals with its cantonal solar initiative. New buildings over 300 m² mandatorily require a solar system. Coordination with BKW or EWB – depending on grid area – determines metering concept, feed-in regulation and commissioning flow. This requires project management that knows both utility processes.

Guide

Battery storage and self-consumption in Zug: when storage, ZEV or vZEV fit a PV system

Assess when battery storage, wallbox, ZEV, vZEV or WWZ self-consumption models in Zug really fit a PV system and when consumption, metering and grid connection need checking first.

Regional service

PV Installation Bern – Roof & Electrical

Bern ranks among the cantons with the highest installed PV capacity per capita. BKW and EWB offer feed-in compensation up to 10.96 Rp./kWh (EWB). In the Bernese Oberland, altitude and snow reflection deliver up to 12% higher winter yields with bifacial modules – placing special demands on mounting structures and load distribution on alpine roofs.

Guide

Battery storage for PV in Aargau: when storage really makes sense

Assess when a battery storage system fits a PV system in Aargau: prepare self-consumption, AEW metering, grid connection, wallbox, heat pump and incentive logic cleanly.

Service

Battery & Wallbox

47% of new Swiss PV systems are installed with battery storage today — we show transparently when LFP batteries (CHF 650–1'000/kWh, 15–20 years) pay off and when they do not. Self-consumption rises from 25–35% (PV-only) to 50–65% with battery and EMS.

Guide

Battery storage incentives in Zurich: what owners should check before the PV quote

How to assess battery storage in Zurich cleanly: city incentives from 1 August 2026, cantonal boundaries, Pronovo for the PV system and the technical check of self-consumption, metering concept and battery size.