Fixed polycrystalline silicon arrays oriented east, west, north and flat
Orienting a solar array due north in the southern hemisphere will maximise its exposure to the sun through the day, on most days of the year. Where a north installation is not possible, arrays might be installed facing the east or west. "Flat" installations are usually avoided, because their surface is more susceptible to dust buildup and soiling.
This solar compass will quantify the impact of installing an array facing east, west or flat, as opposed to the ideal north facing position. Identical 2 kW polycrystalline BP arrays have been installed on a purpose-built frame.
Arrays oriented east or west will receive the same amount of sunlight through the year. In terms of the power they produce, however, there are different benefits associated with either direction.
East-facing arrays receive light in the morning, when temperatures are cooler and the solar panels are operating more efficiently. West-facing arrays receive their light in the afternoon, when the higher temperatures are associated with the day’s peak air-conditioning demand.
The solar compass will contribute meaningful comparative data to the assessment of these relative benefits.
BP Solar is a global business that designs, manufactures and markets solar electricity systems.
| Electricity produced (annual) - north: | 3.2 MWh* |
|---|---|
| Electricity produced (annual) - east: | 2.9 MWh |
| Electricity produced (annual) - west: | 2.9 MWh |
| Electricity produced (annual) - flat: | 3.0 MWh |
| System size: | 4 x 1.98 kW |
| Array area: | 4 x 15.1 m² |
| Number of panels: | 4 x 12 |
| Panel efficiency: | 13.11 % |
| Panel type: | BP 3165J |
| Panel rated output: | 165 W |
| Inverter size, type: | 4 x 2.5 kW, SMA SB 2500 |
| Array orientation: | true north, east and west at 23º tilt flat at 0º tilt |
| Installation completed: | 11 November 2008 |
*This figure is based on an assumption of 1.622 MWh annually, per kWp of installed solar panels. This may prove to be a conservative estimate for Alice Springs.