How to read your electricity bill (and what actually matters)

The five numbers

Everything a solar design needs from your bill comes down to five figures: your total usage for the period (kWh), the number of days it covers, your usage rate (what you pay per kWh - there may be several if you're on time-of-use), your daily supply charge, and - if you already have solar - your feed-in tariff and exported kWh.

From those we derive the number that drives everything: average daily usage. Divide total kWh by billing days. A typical NSW family home lands somewhere between 15 and 30 kWh a day; where you sit in that range, and when you use it, shapes your entire system.

Where retailers hide them

Usage and days usually live in a 'your usage' panel or the detailed charges table, not the summary page. Rates hide in the charges breakdown, often in cents with four decimal places. Time-of-use bills split usage into peak, off-peak and shoulder - if you see those words, the timing of your consumption matters as much as the amount, and that's genuinely useful design information rather than complication.

The number you can mostly ignore: the big 'amount due'. It bundles usage, supply charges, discounts and adjustments - useful for budgeting, weak for design.

Or skip the archaeology

This is exactly what our Bill Analyser does: drop your PDF bill in and it extracts these figures in your browser - the bill itself never leaves your device - then carries them straight into the design tool. Either way, the goal is the same: a design built from your measured usage rather than a guess.