Off-Grid Sizer

Describe your setup

1 What is it for?

2 Where and when

Location Panels mounted Used Days of battery with no sun Panel type Space for panels, mm (length x width, optional) x Max panels that fit (blank = no limit) It's a vehicle (charges from the engine too)

3 What will you run?

Watts and hours per day for each appliance. Typical values are filled in; change them to match yours.

Appliance	Qty	Watts	Hours/day	230 V	Wh/day

1 Your home

Location Electricity use per year, kWh (on your bill; about 4,200 is typical) …or your 2-monthly bill, € (works out the kWh) During the day

2 Roof and panels

Panel Size the system

Roof face 1

Facing Space, mm (length x width) x …or number of panels

Roof face 2 (optional)

Facing Space, mm (length x width) x …or number of panels

3 Battery and tariffs

Battery Import price, c/kWh (day rate on your bill) Export price, c/kWh (your supplier's CEG rate) SEAI grant (home built and lived in before 2021) VAT on the install (%) (0% for solar on homes)

4 Installer settings

System voltage Battery type Peak AC load override (W) Inverter efficiency Solar system losses factor (0.75 typical) Max cable voltage drop (%) Battery to inverter (m, one way) MPPT to battery (m, one way) Panels to MPPT (m, one way) Starter battery to DC-DC (m, one way) Cerbo GX monitoring GX Touch 50 display

Pricing

Margin on non-Victron parts (%) Victron dealer discount (%) (off list) Labour day rate (€) Labour days VAT (%)

Victron parts use the Victron end-user price list (2026 Q4) and are sold at list. Battery, panels, mounts and cable are placeholder buy prices in js/data.js.