SunnyWatly calculators are built around transparent, editable assumptions rather than hidden quote engines.
Solar
Solar generation estimates combine system size with location-based typical daily generation assumptions. Actual output varies with orientation, tilt, shading, weather, inverter limits, losses and equipment.
Electricity savings
Estimated savings separate self-consumed solar from exported solar because imported electricity and exported electricity usually have different values.
Batteries
Battery estimates consider usable capacity, depth of discharge, round-trip efficiency, cycling assumptions and the difference between import and export tariffs. Battery economics can vary widely between households.
EV charging
EV charging estimates use battery capacity, state of charge, electricity tariff, charging efficiency and the lower of charger power and vehicle acceptance limits.
Source hierarchy
We prefer Australian Government, regulators, energy-market bodies, standards organisations and manufacturers for factual inputs. Commercial sources may be used for context, but important program rules should be checked against primary sources.
Updates
Inputs can become stale. SunnyWatly reviews high-impact assumptions when programs or market conditions change and encourages users to replace defaults with their own current rates and quotes.