ROI calculator · 2 minutes

Will a hot water diverter pay back for you?

A diverter redirects your solar surplus into your hot water tank instead of exporting it to the grid at low feed-in rates. This calculator works out the annual savings and payback period for your specific household — and tells you honestly when it doesn't make sense.

Basics

Where you are and what's installed.

Postcode

4-digit AU postcode

Household size (people)

Hot water system type

I own this home (or strata-approved install)The hot water tank is physically accessible

System

Solar, hot water tank, electrical.

Solar system size (kW)

Average daily export (kWh/day)

Check your bill or app for the last 30 days

Tank size (litres)

Element rating (kW)

Most modern elements are 3.6 kW

Electrical phase

Battery installed

Tariff

What you pay and what you earn.

Import rate (c/kWh)

Feed-in tariff (c/kWh)

Current hot water tariff

Controlled load rate (c/kWh, if any)

Leave blank if you're not on controlled load

I'll keep controlled load after installing the diverter (boost only on CL rate)