Solar Basics

How Do Solar Panels Work?

New to solar? Here is how those panels on the roof actually turn sunlight into electricity you can use.

By Andy McMaster

6 min read

Find out what your home actually needs

The basics: Sunlight to electricity

Solar panels work by converting sunlight into electricity. It sounds complex, but the core idea is straightforward.

Each solar panel is made up of dozens of small photovoltaic (PV) cells, usually made from silicon. When sunlight hits these cells, the energy from the light (called photons) knocks electrons loose from the silicon atoms. These loose electrons flow through the cell as an electrical current. That is direct current (DC) electricity.

Your home runs on alternating current (AC), so the DC electricity from your panels passes through a device called an inverter, which converts it to AC. From there, it flows to your switchboard and powers whatever is running in your home: the fridge, air conditioning, lights, everything.

In short: sunlight hits the panels, electrons start moving, the inverter converts the power, and your home uses it. Any excess gets sent to the electricity grid.

Key components in a home solar system

A typical rooftop solar system has four main parts that work together.

Solar panels

Mounted on your roof, these capture sunlight and convert it into DC electricity. Most home systems use 15 to 20 panels.

Inverter

Converts DC electricity from the panels into AC electricity your appliances can use. Usually mounted on a wall near your switchboard.

Switchboard and meter

Your switchboard distributes power around the house. A bi-directional meter tracks what you use from the grid and what you export.

The grid

When your panels produce more than you need, excess electricity flows to the grid. You earn a feed-in tariff for every kWh you export.

What happens during the day vs night

During the day

Your panels generate electricity whenever the sun is out. Your home uses this solar power first. If you are running the washing machine, dishwasher, or air conditioner during the day, you are using free electricity from the sun.

If your panels produce more than your home needs (which is common around midday), the excess automatically flows to the electricity grid. Your energy retailer pays you a feed-in tariff for this exported power, typically 3 to 10 cents per kWh depending on your state and plan.

At night

Once the sun goes down, your panels stop producing. Your home draws electricity from the grid as normal, and you pay your usual electricity rate. This is why it helps to run appliances during the day when your panels are generating. If you have a home battery, it stores excess solar during the day and discharges at night, reducing what you need from the grid.

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How much electricity do solar panels produce?

Output depends on your system size, location, and the time of year. Here is a rough guide for a common 6.6kW system.

CityAverage Daily OutputAnnual Output
Brisbane~27 kWh/day~9,800 kWh/year
Sydney~24 kWh/day~8,700 kWh/year
Adelaide~24 kWh/day~8,600 kWh/year
Perth~26 kWh/day~9,500 kWh/year
Melbourne~21 kWh/day~7,600 kWh/year
Hobart~19 kWh/day~6,900 kWh/year

These are averages. You will produce more in summer (longer, sunnier days) and less in winter. Queensland and Western Australia get the most sunshine, while Tasmania and Victoria get the least.

What affects solar panel output?

Several factors determine how much electricity your panels actually produce.

Roof orientation

North-facing panels produce the most energy in Australia. East and west-facing roofs still work well, typically producing about 10 to 15% less. South-facing is the least ideal.

Roof tilt

The ideal tilt angle roughly matches your latitude. In most Australian cities, that is between 20 and 35 degrees. Flat roofs work too, but panels may need tilt frames.

Shading

Even partial shade from trees, chimneys, or neighbouring buildings can significantly reduce output. Modern panels and optimisers handle shade better than older systems, but avoiding it is best.

Temperature

Solar panels actually lose a small amount of efficiency in extreme heat. They perform best on clear, cool days rather than scorching 40-degree afternoons.

Panel quality and age

Higher-efficiency panels produce more power per square metre. All panels degrade slowly over time, losing roughly 0.5% output per year.

Dust and dirt

A layer of dust, pollen, or bird droppings can reduce output by 5% or more. Rain usually keeps panels clean enough, but a gentle hose-down once or twice a year helps in dry areas.

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Types of solar cells

There are three main types of solar cell technology. In 2026, monocrystalline panels dominate the Australian market.

TypeEfficiencyCostNotes
Monocrystalline20 to 24%Mid-highThe standard choice for homes. Best efficiency and long lifespan. Black appearance.
Polycrystalline15 to 18%LowerOlder technology, less efficient. Blue-speckled appearance. Rarely used in new installs.
Thin-film10 to 13%LowestFlexible and lightweight, but low efficiency. Used in commercial or specialty applications, not typical homes.

For most Australian homes, monocrystalline panels are the clear choice. They offer the best efficiency per square metre of roof space and prices have come down significantly over the past decade.

Next steps

Now that you understand how solar panels work, the next step is figuring out what size system you need and how much it will cost.

The next step

If you're considering solar panels or batteries for your home, Andy and the team can match you with one Why Solar Approved installer near you for a free written quote, and fifteen minutes with a solar expert before you sign.

Headshot of Andy McMaster, Solar Installer Partner Relations at Why Solar

Written by

Andy McMaster

Solar Installer Partner Relations

Connects homeowners with trusted, vetted solar installers across Australia. Andy works directly with installation companies to ensure quality standards and helps homeowners through the quoting process.

If you have any questions about the information in this guide, email andy@whysolar.com.au or call +61 2 5657 6527.

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