Choose the objective first
An orientation cannot be “best” until the design objective is stated. Common objectives include annual energy, self-consumption, production during a constrained export window, seasonal output, usable system size or lowest installed complexity.
What direction changes
- North: the Australian Government's YourHome guide gives north as a general southern-hemisphere rule for annual solar exposure.
- East or north-east: moves more of the production profile towards morning.
- West or north-west: moves more of the profile towards afternoon.
- Split arrays: can broaden the production window, subject to shade and suitable string or MPPT allocation.
These are profile descriptions, not financial conclusions. Local irradiance, horizon, shade and roof pitch determine the energy. Interval consumption, tariffs, export controls and battery operation determine its value.
Field workflow
- Mark every usable roof face, pitch and obstruction.
- Record recurring shade across the day and note seasonal uncertainty.
- Confirm the customer's objective and obtain interval load data where available.
- Model realistic layouts with the same weather, losses and equipment assumptions.
- Check that differently performing groups are allocated to suitable strings and MPPT inputs.
- Record export limits, tariff assumptions and battery controls separately from the yield model.
Tilt is not only an energy calculation
Tilt changes solar access and seasonal production, but the installed decision also includes the existing roof, mounting certification, wind actions, row spacing, drainage, debris and safe access. Do not recommend a tilt frame from a latitude rule alone. Compare the modelled gain with the added design, installation and maintenance consequences.
What to hand over
Keep the proposed orientation, tilt, shade assumptions, annual estimate and production profile together. State whether the layout was chosen for annual yield, time-of-day fit or a physical constraint. The estimate is a design aid, not a production guarantee.