Solar panel payback calculator

How this calculator works

Yearly generation = kW × peak sun hours × 365 × efficiency. Every kWh you use yourself saves the full electricity price, and each one you export earns only the feed-in tariff. So the share you self-consume matters most.

Worked example: a 6.6 kW system with 4.2 sun hours at 80% makes about 8,094 kWh a year. Using 40% at 32c and exporting the rest at 5c is worth about $1,279 a year, so a $6,500 system pays back in about 5.1 years.