Most people know solar panels turn sunlight into electricity, but exactly how they do that is less obvious. Understanding how a system uses sunlight to power a home or business can help you get a clearer idea of the right setup and what you’re actually paying for if you’re in the process of buying solar.
After more than 15 years installing solar across Melbourne, we know technical language can make a fairly straightforward process sound more complicated than it actually is. The clearest way to understand how solar works is to start with the big picture, then look at each component.
Solar at a glance:
- Every 1 kW of solar panel capacity can generate around 3.5 to 5 kWh per day, depending on the location and installation of the system, according to the Australian Government’s Solar Consumer Guide.
- Solar panels work by producing direct current electricity, which is converted into usable alternating current electricity by an inverter.
- Solar power is used when it’s produced. Any surplus electricity can charge a battery to be used later or be sent to the grid, while the grid can supply any shortfalls.
What is solar energy?
Solar energy refers to the light and heat produced by the sun, which is considered a naturally renewable energy source. There are different ways to capture it, with the specific type used to generate electricity to power a home or business known as solar photovoltaic energy, also known as solar PV.
A solar PV system uses panels consisting of photovoltaic cells, or solar cells, which convert sunlight directly into electricity. Once it’s converted into electricity, that solar power can be used to power lights, appliances and equipment, the same as using electricity powered from the grid. The difference is that the electricity is generated on the property while the sun is shining.
Fun fact: Rooftop solar generated 14.2% of Australia’s electricity during the second half of 2025, according to the Clean Energy Council.
How does solar power work? A practical example.
Imagine it’s 1pm. The solar system is producing around 5 kW while the property is using 3 kW to power appliances. This is how that process is happening:
Step 1. Sunlight creates electricity inside the panels.
Every solar panel contains photovoltaic cells, which are usually made from silicon. When sunlight reaches these cells, it creates an electrical current known as direct current, or DC, electricity.
Solar panels respond to light rather than heat, so hot weather isn’t required. They can still generate electricity on cool or cloudy days, although output usually drops when less sunlight reaches the cells.
Step 2. The inverter makes the electricity usable.
The DC electricity then travels to the inverter, which converts it into alternating current, or AC, electricity. This is the type of power used by homes and businesses.
The inverter also monitors system performance and can shut down the system if it detects certain electrical or grid faults.
Step 3. The property uses 3 kW.
Once converted, the electricity travels through the property’s switchboard to the electrical circuits. For example, 3 kW powers lights, appliances, air conditioning and other equipment running at that time.
If the system generates less electricity than is needed to run appliances, lights and other household or business equipment, the grid automatically supplies the difference. You don’t need to switch between solar and grid mode manually. It just happens.
Step 4. The remaining 2 kW is stored or exported.
Now, if the property is only using 3 kW of the 5kW being generated, this leaves 2 kW of surplus electricity. Depending on the setup, this power can:
- Charge a solar battery to power appliances and such later.
- Be exported to the electricity grid.
- Be divided between the battery and grid according to the system settings.
A compatible electricity meter records how much power is imported from and exported to the grid. The electricity retailer uses this information to calculate usage charges and feed-in tariff credits.
How Solar Generation Changes Throughout the Day
Solar energy isn’t generated consistently all day. It rises and falls depending on the sun’s position, cloud cover, shade, the temperature, panel direction and other factors. This can then impact how much you have to rely on the grid.
| Time of Day | Solar Generation | What May Happen |
|---|---|---|
| Early morning | Low and gradually rising | The property may use a mix of solar and grid electricity. |
| Middle of the day | Usually at its highest | Solar can power the property, with surplus electricity sent to a battery or the grid. |
| Late afternoon | Gradually falling | The grid or battery may start covering more of the property’s usage. |
| Night | None | Electricity either comes solar energy stored in a battery or the grid. |
On average, Australian homes use around 11 to 23 kWh of electricity per day. How much of this could be covered by solar depends on what time of day it’s used.
For example, a household that’s empty for most of the day may export much of its midday generation to a battery or the grid. While a home running a pool pump, air conditioning or home office setup during the day may use more of its solar electricity directly. A lot of businesses also have quite strong daytime usage, which aligns well with solar generation.
“We look at both how and when a property uses electricity in making a recommendation for a solar system. Two properties can have quite similar bills and still need different solar designs because their usage patterns are completely different.”
What affects how much solar power a system produces?
It’s important to remember a system’s rated size shows how much power it can produce under standard test conditions, not what it will actually generate for every house. How solar energy works in reality can depend on a few factors, including:
| Factor | How it Affects Generation |
|---|---|
| System size | The higher the panel capacity, the more generation potential it has, providing it’s supported by the design and inverter. |
| Panel direction and angle | North-facing panels often produce the highest daily total, while east and west-facing panels can spread it across the morning and afternoon. |
| Shade | Trees, buildings, roof features and debris can restrict sunlight reaching parts of the system. |
| Time and season | Longer summer days generally provide more generation time than shorter winter days. |
| Cloud cover | Panels still work under cloud cover, although it does usually mean lower output. |
| Panel temperature | While sunlight is what generates electricity, very hot panels may convert it less efficiently. |
| System condition | Dirt, damaged components and electrical faults may reduce performance. |
Together, these factors affect how much solar power is available to use onsite, which can reduce how much electricity the property needs to buy from the grid.
This is why a solar quote based only on system size can be misleading. Teaslec calculates based on the roof, surrounding shade, local conditions and how the panels and inverter work together.
That property-by-property approach helped one homeowner who called Teaslec who had been told by several other solar companies that their shaded roof was unsuitable. After assessing the property, Brad and our team found a way to make solar work, showing why generation potential needs more than a standard system-size estimate.
More FAQ About Solar Energy
How Solar Power Could Work for Your Property
Understanding how solar works gives you a better starting point for finding a system that suits your property. When you speak with Teaslec, bring along:
- Recent electricity bills and an idea of when you use the most power.
- Details about the available roof space, direction and surrounding shade.
- Future plans such as battery, electric vehicle or business expansion.
These details help our team recommend a system size and setup based on how your property will actually use solar power. With more than 15 years installing solar across Melbourne, Teaslec can explain your options and provide a free quote tailored for your needs. Get your free solar quote.
