Calculators
How many years until solar pays back?
Adjust consumption, system size, price and subsidy. The calculator estimates generation, savings and payback including panel degradation and price growth.
Common questions
How much does a home solar system generate?
The calculator starts from 1000 kWh per installed kWp a year. Your installer's quote should give an expected yield for your roof and postcode, so enter that. In Australia north-facing panels generate the most; east- and west-facing panels produce a little less, and south-facing or shaded panels noticeably less.
What is a typical payback?
It depends on the installed price after the STC discount, how much of the output you use yourself, your usage rate and your feed-in tariff. Prices vary a lot by city and roof, so put your own quote into the calculator rather than trusting a national average.
What is self-consumption and why does it matter?
The share of your solar output you use yourself. Each kWh you use saves the full usage rate, while exports earn only the feed-in tariff, which retailers set and which has been falling. Running the dishwasher, hot water or an EV charger in the middle of the day raises it.
Is a time-of-use plan worth it with solar?
Often, if you can use power in the middle of the day and keep usage down in the 4 pm to 9 pm peak. Compare the whole plan, including the feed-in tariff and daily supply charge, not one rate.