Self-Consumption

The core concept

Self-consumption is the share of your total solar generation that gets used by appliances in your home at the same time it’s being produced. If your 6.6 kW system generates 30 kWh on a given day and your home uses 18 kWh of it directly (with 12 kWh exported), your self-consumption rate is 60%.

The counterpart metric is self-sufficiency - the share of your total household electricity needs met by solar. These are related but different. A household with a large solar system might self-consume only 40% of their solar generation (because they export a lot) but meet 90% of their energy needs from solar.

Why it matters more than system size

With feed-in tariffs in the 4–10¢/kWh range and import rates at 28–40¢/kWh, the financial value of a kWh you consume from your own solar is 3–8× higher than a kWh you export.

This means optimising for self-consumption often delivers better returns than maximising system size. Running high-consumption appliances during the middle of the day - dishwasher, washing machine, EV charging - shifts load into the generation window and captures that higher value.

Typical self-consumption rates in Australia

Self-consumption varies enormously by household type and behaviour:

• Working household, no battery: 25–40%. Most generation happens when no one is home
• Retired or home-based household: 50–65%. More daytime load aligns with generation
• Household with EV and daytime charging: 55–70%
• Household with battery storage: 70–90%

A battery doesn’t increase generation - it shifts the consumption window, allowing you to use solar energy generated at noon to power the evening load.

Improving self-consumption without a battery

The cheapest ways to increase self-consumption:

1. Set your dishwasher and washing machine on a timer to run at midday
2. Charge your EV during the day rather than overnight (if you have daytime access to your car)
3. Pre-heat or pre-cool the house using solar before you arrive home
4. Heat water using a solar diverter that dumps surplus generation into your hot water system rather than exporting it

A solar diverter (like the iBoost or Solarman) can cost $500–$700 installed and increases hot water self-consumption substantially - often delivering a better return per dollar than adding more panels.