How to optimise solar system tilt

Crystalline solar PV panels produce the most power when they are pointed directly at the sun. In Australia, solar modules should face north for maximum electricity

production. The orientation of the panels will often have a greater effect on annual energy production than the angle they are tilted at.

The current feed-in tariff structures in Australia result in east-west-facing systems generating an optimal return on investment, especially if the property utilising solar

feed-in tariffs has low electricity usage in the middle of the day.The Clean Energy Council’s (CEC) solar guidelines for residential PV recommend a minimum tilt of 10° to ensure self-cleaning by rainfall; and for grid-connected PV systems, CEC recommends positioning panels at the angle of latitude to maximise the amount of energy produced annually.The best return on investment will be generated for the solar project owner if the system is designed based on the electricity usage pattern of the property on which

the project is installed.

Most Australian homes have a roof pitch of 20 – 30°, according to the CEC’s guidelines; if a roof slope is not ideal, a mounting frame can correct the orientation and elevation

of panels. On flat-roof buildings (particularly commercial installations), panel arrays are usually installed on racks at an angle of 15–30°. Some companies typically only

install at 15°; this allows for more modules to be placed on a roof, with less wind loads,lower cost, and the same yield. Yield is surprisingly insensitive to inclination.The installation site, roof material, roof angle, the size and quantity of solar panels and the number of module rows used will determine the dimensions, quantity and layout

of framing components required for installation.Keep in mind that a lower tilt can allow you to fit more panels on the same roof, and also that tilts generate shadows - make sure there’s sufficient space between the rowsin a solar installation.