Azimuth
The compass direction your solar panels face. In WA, north-facing (0deg azimuth) maximises annual energy harvest.
Battery Cycle
One full charge and discharge of a battery. Most home batteries in WA are rated for 6,000-10,000 cycles over their warranty life.
Capacity Factor
The ratio of actual energy output to maximum possible output over a year. It rises with sunshine hours and falls with shading and system losses, so Perth's strong sun works in its favour.
CEC
Clean Energy Council -- the Australian body that approves solar products for sale and rebate eligibility. Installer accreditation moved to Solar Accreditation Australia (SAA) in 2024.
DEBS
Distributed Energy Buyback Scheme -- WA's feed-in tariff program managed by Synergy, paying 2c/kWh off-peak or 10c/kWh during the 3pm-9pm peak window.
Degradation
The gradual decline in panel output over time, typically 0.4-0.5% per year. Quality panels guarantee at least 80% output after 25 years.
Depth of Discharge
The percentage of a battery's capacity that has been used. Most lithium batteries allow 90-100% DoD without damage.
Feed-in Tariff
The rate your retailer pays you for excess solar energy exported to the grid. In WA, DEBS rates vary by time of day.
Grid-connected
A solar system connected to the Western Power network, allowing you to export surplus energy and draw power when needed.
Hybrid
An inverter or system that manages both solar panels and battery storage, allowing grid-connected operation with backup capability.
Inverter
Converts DC electricity from solar panels into AC electricity used by your home appliances and the grid.
kW
Kilowatt -- a measure of power (rate of energy flow). A 6.6kW system can produce up to 6,600 watts at peak output.
kWh
Kilowatt-hour -- a measure of energy. A typical Australian home uses around 18 kWh per day; your bill shows your own figure.
Microinverter
A small inverter attached to each individual panel, enabling panel-level optimisation and monitoring. Popular for shaded roofs in WA.
Off-grid
A solar and battery system that operates independently from the electricity grid, common in remote WA properties.
Optimiser
A DC-DC converter attached to each panel to maximise output. Used with string inverters to handle partial shading.
Peak Sun Hours
The equivalent hours of full-strength sunlight per day. Perth averages 5.0 peak sun hours annually (higher in summer, lower in winter), among the best in Australia.
Performance Ratio
The ratio of actual system output to theoretical maximum, accounting for losses from heat, wiring and the inverter. WattMate's estimates assume 85%.
Self-consumption
The percentage of solar energy you use directly rather than exporting. Higher self-consumption means greater savings in WA.
STC
Small-scale Technology Certificate -- a federal rebate mechanism. Each STC represents 1 MWh of renewable energy and reduces your upfront cost.
String Inverter
A central inverter that converts power from a 'string' of series-connected panels. Cost-effective for unshaded WA roofs.
Tilt Angle
The angle of your panels relative to horizontal. In Perth (latitude ~32deg), a tilt of 28-32deg optimises year-round production.
