Going solar should not mean learning a new language. But between kilowatts, certificates, inverters, and feed-in tariffs, it can certainly feel that way. We created this comprehensive solar jargon buster so you can understand exactly what every term means, without the confusion or the sales spin.
Whether you are researching solar for the first time or trying to make sense of a quote you have received, bookmark this page and refer back to it whenever you encounter a term you are not sure about.
AC (Alternating Current)
The type of electrical current used by your home appliances. Solar panels produce DC (direct current) electricity, which must be converted to AC by an inverter before it can power your home or be exported to the grid. The electricity grid in Australia operates on AC at 240 volts and 50 hertz.
Azimuth
The compass direction your solar panels face, measured in degrees from north. In Australia, north-facing panels (0 degrees azimuth) typically produce the most energy overall. East-facing panels produce more in the morning, and west-facing panels produce more in the afternoon. Your installer will assess the optimal azimuth based on your roof orientation and energy usage patterns.
Battery Capacity
The total amount of energy a solar battery can store, measured in kilowatt-hours (kWh). For example, a 10kWh battery can theoretically store 10 kilowatt-hours of electricity. However, the usable capacity is always less than the total capacity due to depth of discharge limits. Common residential batteries in Australia range from 5kWh to 15kWh.
CEC (Clean Energy Council)
Australia's peak body for the clean energy industry. The CEC maintains lists of approved solar products (panels and inverters) and accredits solar installers. Choosing a CEC-accredited installer and CEC-approved products is essential to qualify for STCs (the government solar rebate). Smart Solar Group is a CEC-accredited installer.
Cell (Solar Cell)
The individual photovoltaic unit within a solar panel that converts sunlight into electricity. Most modern solar panels contain 60, 66, or 72 cells arranged in a grid pattern. Each cell is made from semiconductor material, typically silicon, that generates a small electrical current when exposed to light. Multiple cells are wired together within a panel to produce usable voltage and current.
Clipping
When a solar array produces more DC power than the inverter can convert to AC, the excess is 'clipped' or lost. This commonly occurs when the panel capacity exceeds the inverter's rated capacity (known as oversizing). A small amount of clipping is normal and intentional in well-designed systems because oversizing panels relative to the inverter optimises overall annual production.
Cycle Life
The number of complete charge-discharge cycles a battery can perform before its capacity degrades to a specified level (usually 70-80% of its original capacity). A battery with a cycle life of 6,000 cycles can be fully charged and discharged 6,000 times. Longer cycle life means better long-term value. Premium lithium batteries typically offer 6,000 to 10,000 cycles.
DC (Direct Current)
The type of electrical current produced by solar panels. DC flows in one direction, unlike AC (alternating current) which reverses direction many times per second. Since your home appliances and the grid use AC, a solar inverter is required to convert DC to AC. Some specialised appliances and battery systems operate on DC directly.
Degradation
The gradual reduction in a solar panel's power output over time. All solar panels degrade slowly, typically losing 0.3% to 0.5% of their output per year. Premium panels degrade more slowly. A panel with a 25-year performance warranty might guarantee at least 80-84% of its original output after 25 years. Degradation is a natural process and is factored into system performance projections.
Depth of Discharge (DoD)
The percentage of a battery's total capacity that can be used before recharging. For example, a 10kWh battery with a 90% DoD has 9kWh of usable energy. Using a battery beyond its recommended DoD can accelerate wear and shorten its lifespan. Modern lithium-ion batteries typically have a DoD of 90-95%, meaning you can use almost all the stored energy.
EV (Electric Vehicle) Charging
The process of charging an electric car using electricity from your solar system, the grid, or a combination. A typical EV charger draws between 2kW (slow charge) and 7kW (fast home charge). Charging your EV with solar energy instead of grid power can save you thousands of dollars per year on fuel costs. Larger solar systems (10kW+) are recommended if you plan to charge an EV at home.
Export
When your solar system produces more electricity than your home is using at that moment, the excess is sent (exported) back to the electricity grid. You receive a credit for exported energy through the feed-in tariff. Maximising self-consumption (using the energy yourself) is generally more financially beneficial than exporting, since feed-in tariff rates are lower than the price you pay for grid electricity.
Feed-in Tariff (FiT)
The rate your electricity retailer pays you for solar energy you export to the grid, measured in cents per kilowatt-hour (c/kWh). In Queensland, feed-in tariffs currently range from approximately 5c to 12c per kWh depending on your retailer and plan. Historically, some early solar adopters in QLD received premium feed-in tariffs of 44c/kWh, but these legacy rates are no longer available for new installations.
Grid-Connected System
A solar power system that is connected to the main electricity grid. This is the most common type of residential solar installation in Australia. Grid-connected systems allow you to draw power from the grid when your solar is not producing enough (at night or on cloudy days) and export surplus solar energy to the grid for a feed-in tariff. No battery is required for a grid-connected system, although one can be added.
Hybrid System
A solar system that includes both grid connection and battery storage. A hybrid inverter manages the flow of electricity between the solar panels, battery, home loads, and the grid. This setup gives you the best of both worlds: you can store excess solar energy in the battery for use at night, but you also have the grid as a backup. Hybrid systems offer the most flexibility and can often provide backup power during grid outages.
Inverter
The device that converts the DC (direct current) electricity produced by solar panels into AC (alternating current) electricity used by your home and the grid. The inverter is often called the 'brain' of the solar system because it also manages power flow, monitors performance, and ensures the system operates safely. There are three main types: string inverters, microinverters, and hybrid inverters.
kW (Kilowatt)
A unit of power equal to 1,000 watts. In solar, kW is used to describe the capacity or size of a system. For example, a 6.6kW solar system can produce up to 6,600 watts of power at peak output. A system's kW rating indicates its maximum instantaneous power output under ideal conditions (known as Standard Test Conditions). Do not confuse kW with kWh, which measures energy over time.
kWh (Kilowatt-hour)
A unit of energy equal to using 1,000 watts of power for one hour. This is how your electricity usage and solar production are measured. Your electricity bill charges you per kWh consumed. For reference, a typical Queensland household uses 15-25 kWh per day. A 6.6kW solar system in North Queensland typically produces 25-30 kWh per day on average.
Microinverter
A small inverter attached to each individual solar panel, converting DC to AC at the panel level. Unlike string inverters (which connect multiple panels to a single inverter), microinverters allow each panel to operate independently. This means that if one panel is shaded or underperforming, it does not affect the output of the other panels. Microinverters are ideal for roofs with partial shading or multiple orientations.
Monitoring System
Software and hardware that tracks your solar system's real-time performance, showing how much energy is being produced, consumed, exported, and (if applicable) stored in your battery. Most modern systems include smartphone apps that let you check performance from anywhere. Monitoring is crucial for detecting issues early and ensuring your system is performing as expected.
Net Metering
A billing arrangement where the electricity you export to the grid is offset against the electricity you import from the grid. In some configurations, your electricity meter measures the net difference between what you produce and what you consume. While true net metering (where export and import rates are equal) is not standard in Australia, the combination of self-consumption and feed-in tariff credits provides a similar economic benefit.
Off-Grid System
A solar system that is completely independent of the electricity grid. Off-grid systems require significant battery storage to provide power when the sun is not shining, and often include a backup generator for extended periods of low solar production. These systems are typically used in remote areas where grid connection is not available or prohibitively expensive. They require careful sizing and design to ensure reliable power supply year-round.
Optimiser (DC Optimiser / Power Optimiser)
A device attached to individual solar panels that maximises the DC output of each panel before it reaches the central string inverter. Like microinverters, optimisers allow each panel to perform independently, mitigating the effects of shading on one panel affecting the others. They are a middle-ground solution between standard string inverters and full microinverter systems.
Peak Sun Hours (PSH)
The number of hours per day when solar irradiance averages 1,000 watts per square metre. This is a standardised way to compare solar potential across different locations. North Queensland enjoys approximately 5.0 to 5.8 peak sun hours per day on average, which is among the highest in Australia and makes it an excellent location for solar energy.
PV (Photovoltaic)
The technology that converts sunlight directly into electricity using semiconductor materials. 'PV' is the term used across the industry to describe solar panels and solar power systems. A photovoltaic cell is the basic building block; multiple cells form a panel (or module), and multiple panels form an array. The photovoltaic effect was first observed in 1839 by French physicist Edmond Becquerel.
Self-Consumption
The proportion of solar energy you generate that is used directly by your household rather than exported to the grid. Higher self-consumption rates lead to greater savings because the value of using your own solar electricity is worth more than the feed-in tariff you receive for exporting it. Batteries, timers on appliances, and smart energy management all help increase self-consumption.
Shading Analysis
An assessment performed during the site survey to identify any objects (trees, buildings, antennas) that may cast shadows on your solar panels throughout the day and across seasons. Even partial shading can significantly reduce the output of a solar system, particularly with string inverter configurations. A thorough shading analysis ensures your system is designed for optimal performance.
Single-Phase vs Three-Phase Power
Single-phase is the standard power supply for most Australian homes, delivered through two wires. Three-phase power uses three wires and delivers more power, often found in larger homes or homes with high-demand appliances like large air conditioners or workshop equipment. The type of power supply you have affects inverter selection and the maximum solar system size you can install without an export limit.
STC (Small-scale Technology Certificate)
A financial incentive created by the Australian government's Small-scale Renewable Energy Scheme (SRES). Each STC represents one megawatt-hour of renewable energy your system is expected to generate. The number of STCs you receive depends on your system size, location, and the years remaining until 2030. STCs are traded on a market and their value is applied as an upfront discount on your solar installation cost. In Queensland, the STC rebate typically reduces the cost by $2,500 to $4,000+ for a standard residential system.
String Inverter
A central inverter that connects to multiple solar panels wired together in one or more 'strings'. String inverters are the most common and cost-effective inverter type for residential installations. However, because all panels in a string share the same current, the performance of the whole string can be limited by the weakest-performing panel (for example, one that is shaded). String inverters work best on roofs with consistent orientation and minimal shading.
Tilt Angle
The angle at which your solar panels are mounted relative to the horizontal ground. The optimal tilt angle depends on your latitude and the time of year. In North Queensland (around 19 degrees south latitude), a tilt angle of approximately 15 to 20 degrees generally maximises annual energy production. Most residential panels are mounted flush to the roof pitch, which in Queensland is usually close to optimal.
Time-of-Use (ToU) Tariff
An electricity pricing structure where the cost per kWh varies depending on the time of day. Typically, electricity is more expensive during peak periods (late afternoon and evening) and cheaper during off-peak periods (overnight and midday). Understanding your ToU tariff is important for maximising solar savings, as you can shift energy-intensive tasks to times when your solar is producing, or use stored battery energy during expensive peak periods.
Watt (W)
The basic unit of electrical power. One watt equals one joule of energy per second. Solar panels are rated in watts (e.g., a 400W panel). Your home appliances also have watt ratings: a standard LED light might use 10W, a fridge 150W, and an air conditioner 2,000W (2kW). Understanding watts helps you estimate how much solar production you need to offset your consumption.
Commonly Confused Terms
kW vs kWh
This is the most common source of confusion in solar. Think of it this way:
- kW (kilowatt) is a measure of power — the rate at which energy is produced or consumed at any given instant. It is like the speedometer in your car showing how fast you are going right now.
- kWh (kilowatt-hour) is a measure of energy — the total amount of power used over time. It is like the odometer showing the total distance you have travelled.
A 6.6kW system producing at full capacity for one hour generates 6.6kWh of energy. Over a full day in Queensland, that same system might produce 25-30kWh because sunlight intensity varies throughout the day.
String Inverter vs Microinverter
Both do the same fundamental job (convert DC to AC), but they do it differently:
- String inverter: One central unit handles all panels. More affordable but all panels in a string are limited by the weakest-performing panel. Best for unshaded roofs with a single orientation.
- Microinverter: Each panel has its own tiny inverter. More expensive but each panel operates independently. Ideal for shaded or multi-orientation roofs.
Grid-Connected vs Off-Grid vs Hybrid
- Grid-connected: Solar panels plus inverter connected to the grid. No battery. The simplest and most affordable option. You use solar during the day and grid power at night.
- Hybrid: Solar panels plus inverter plus battery, still connected to the grid. Store excess solar in the battery for nighttime use, with the grid as backup. The best option for most homeowners who want energy independence.
- Off-grid: Completely independent from the grid. Requires substantial battery storage and often a backup generator. Used primarily in remote locations where grid connection is unavailable.
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