Battery savings calculator

Estimate cost, STCs, savings and payback.

For a more useful result, grab a recent electricity bill and enter your average daily grid use, solar exports and tariffs.

1. Your energy use

Average daily grid use (kWh)

Average daily solar export (kWh)

Grid import rate (c/kWh)

Solar feed-in tariff (c/kWh)

Share of grid use after solar hours

Round-trip battery efficiency (%)

2. Battery scenario

Usable battery capacity (kWh)

Installed price before battery STC benefit ($)

Expected installation period

Assumed value per STC ($)

Why is STC value editable? STCs can be traded in the open market or clearing house. The clearing-house price is fixed at $40 excluding GST, while open-market prices vary. An installer or retailer may also apply its own commercial terms when assigning the benefit.

How this estimate works

Battery Simple estimates daily energy that could be shifted by taking the lowest of: your available solar exports, your grid demand after solar hours, and the battery's usable daily throughput after the efficiency assumption. It values that shifted energy at the difference between your grid import tariff and solar feed-in tariff.

This is deliberately simpler than a professional interval-data model. It does not model seasonal solar variation, time-of-use tariffs, demand charges, battery degradation, finance costs, VPP payments, backup reserve settings or wholesale market participation.