Your location and seasonal changes can effect how much power your system will produce. The orientation and angle of the panels can also have an effect on annual energy production. Placing panels in a north-facing direction is optimal, however placing panels on a west or east facing roof will still produce a substantial amount of power. In New Zealand, panels will not perform well if they face to the south. The tilt angle is also  important to maximize the energy created from your panels. Most New Zealand homes have a roof pitch of 20° to 30° which in most situations is perfect. A minimum tilt of 5° to 10° is recommended to ensure self-cleaning by rainfall to help keep the system running at its best. A regular cleaning schedule is also recommended.