The right solar system size depends on your household’s electricity use, roof space, budget, shading and when you use the most power. Reviewing your electricity bills can help an accredited solar installer estimate a suitable system and explain how much energy may be used directly or exported to the grid. Your local network’s export limits and any available incentives can also affect the practical size and cost. Compare proposals carefully, and check current guidance with your electricity provider and energy.gov.au before deciding.