If you’re wondering, “what size solar system do I need”, you’re not alone. Data from the Australian Photovoltaic Institute shows there are over 3.92 million PV installations in Australia. Plus, having a solar panel system is effective since it can help reduce electricity bills. Plus, it allows you to be almost fully off-grid and generate industry yourself. However, selecting the right solar system can be difficult. That’s why people try to focus on finding “how much solar power do I need” or they try to find a “what size solar system do I need calculator”. Thankfully, finding that info is easier than before, and we are here to help!
What is a solar system?
A solar power system is also known as a photovoltaic or PV system. The role of such a system is to help you generate electricity from solar power. The system includes a variety of tools, from solar panels to an inverter, solar batteries, and other items. All of these are extremely important, as they help transform solar energy into electricity.
Where solar panels can be used in daily life?
Residential electricity generation
Solar power has quickly become one of the primary ways Australians use energy. Many families install solar panels on their roofs to convert sunlight to electricity for use inside the home. They utilize this renewable source by powering appliances during the hours of maximum sunlight using air conditioners (2–5 kWh/h), water heaters (3–6 kWh/h), electric vehicle charging (15–60 kWh/h), dishwashers(1 – 2.5 kWh/h), washing machines(0.5 – 2 kWh/h) and clothes dryers (3-5 kWh/h) with solar energy during maximum sun hours. This means they use less electricity from the grid and pay less for their electricity. Also, the government has made it cheaper to install solar panels at home. At the same time, the Feed-in Tariff (FiT) allows users to sell excess electricity back to the grid and make money.
| Appliance | Runtime with a 6.6 kW Solar System |
| Air Conditioner (Cooling) | 5 – 12.5 hours |
| Water Heater | 4 – 8 hours |
| Electric Vehicle Charging | 0.5 – 1.5 hours (partial charge) |
| Dishwasher | 10 – 25 hours (multiple cycles) |
| Washing Machine | 12.5 – 50 hours (multiple cycles) |
| Clothes Dryer | 5 – 8 hours |
Backup power and energy storage
Power outages in some parts of Australia are caused by extreme weather events like forest fires, thunderstorms, and hurricanes. To quickly address such problems, you can use the most suitable solar generator size to collect efficiently solar power and store it as electricity. Using a solar generator to collect extra solar power during the day and using your home battery storage system to store this extra electricity at night or when there are power outages ensures a stable power supply at home at all times and any power shortages. Furthermore, Peak Shaving systems can help lower electricity costs: charging when prices are low while discharging when prices increase will make sure a constant power source at home! To take full advantage of such capabilities, you must build home battery backup system as soon as possible so it’s ready when disaster strikes!
Off-grid or RV living
Solar panels provide reliable power when living in an RV or camping. RV enthusiasts in Australia frequently utilise them to power appliances like refrigerators, lighting and air conditioners in their vehicle. Choosing the right solar panels needed for RV can make your trip more convenient and give you a longer range. If you also have a portable solar charger, you can power devices like mobile phones, GPS and drones. This makes exploring the wilderness and hiking safer and more reliable.
How to calculate my solar system size?
Step 1: Determine your energy consumption
Before asking how many solar panels do I need, it’s a good idea to know your average energy consumption for a month. Try to collect the last year’s worth of electricity bills, add up the total amount of kWh you consumed, and then split it into 12. That will give you the monthly average.
Step 2: Calculate daily usage
Once you have that number, you will need to divide the number by 30. On average, Australian homes tend to consume 600-900 kWh a month. In that case, that means 900/30 = 30 kWh a day. It’s just an example; your consumption will be more or less, depending on the situation. But it’s a great way to narrow down your monthly consumption, so keep that in mind.
Step 3: Determine solar panel output
You want to know how many sun hours you can expect based on your region. For Australia, you can use the Bureau of Meteorology map. If you live in a region where you have five sun hours a day and you need 30 kWh a day, then you require a 6 kW solar array. That way, you can go to a solar panel provider and see how many panels are required to provide at least 6 kWh a day, ideally more, so you can even store a bit.
Step 4: Calculate the number of panels needed
It’s important to know how much energy is generated per solar panel. Generally, a single solar panel generates anywhere from 250 to 400 watts an hour. Taking our example above, at 6 kW needed per hour, you will need 15 panels if each panel generates 400 watts. That’s because 6000 watts/400 = 15.
Step 5: Account for system losses
However, not every solar system will be perfect. There are many situations where solar panels won’t be able to generate the designated amount all the time. It’s a good idea to add some extra panels. In most cases, having 20-25% more panels than the fixed amount you need will help. That will provide you with some leeway while also accounting for the extra challenges that might arise.
Step 6: Final system size
Sticking with the example above, we can add 1.2 kWh extra to the 6 kWh required. So, how many PV panels do I need? In this example, you should add 3 more, at least, maybe 4. The total amount of panels will be 15+ 3 or 4, so around 18-19 panels will suffice.
Determine how many solar panels will I need: other factors
Sunlight hours per day
When you determine how many solar panels will I need, you have to consider the number of sunlight hours you get per day. You can check the Bureau of Meteorology map to see how many sunlight hours you get in your area. That will help determine the number of solar panels required. And as we said, it always helps to add more so you can circumvent any losses, lack of sunlight during the day, etc.
Roof space
Of course, we may want to add as many solar panels as we want, but there are limitations. For example, the roof size will restrict you to only a specific number of panels. That’s why you want to talk with a team of experts and see how they set up solar panel system for homes. Plus, you can ask them how many panels will fit, and if it will provide enough energy for the property.
Budget
The average cost per solar panel starts at $200, and it can go up to $600 or more. Prices depend size and other features. However, when we talk about the total cost of a solar system, on average it can be anywhere from $24k to $33k, depending if it’s low or high end. Yet that’s before tax credits. With the federal tax credit, those numbers drop to approximately $17k and $23k, respectively.
How many PV panels do I need for common appliances?
It’s very important to know the wattage requirements of common appliances, which you can find in their manual. On average, a fridge will consume around 500 to 800W, an oven can go 2000 to 5000W, while a coffee maker consumes 500 to 100W. An HVAC unit can end up consuming 3000W, a water heater 4000W, whereas a washing machine consumes 400 to 2500W, depending on the model.
In total, having around 15-18 solar panels should cover most appliances. Create a list with all your appliances, then add it up to see your total wattage requirements. After that, you add 20% extra, and start checking the amount of watts provided by a solar panel, and then divide the total wattage requirements to that. For around 7.2 kWh, you should be ok with having around 18 solar panels.
How to set up a solar panel system?
If you want to set up solar panel system, we recommend working with a team of experts. DIY-ing this can be very challenging, and you can easily run into problems. But in short, these are the steps you have to go through when installing the solar system:
- Set up scaffolding
- After that, install the solar panel mounts
- You will need to mount the solar panels
- Once that is done, secure the electrical wiring
- Now you have to connect the solar inverter
- Connect the inverter to the solar battery
- Lastly, you will need to test the system and monitor it
What size solar generator do I need?
It’s very important to ensure that you know how much wattage is required on a daily basis by your appliances. On average, a 2000W solar generator and above should fit most homes, as it will cover the use of general appliances, while having extra power for any additional requirements. Having over 2000W from the solar generator is preferred, in case you plan on buying more appliances and want to use multiple ones at once!
Out of the different options available on the market, the EcoFlow DELTA Pro Portable Power Station is an excellent solar generator that can provide around 3600W-7200W for your appliances, which will fit most of your appliances. Remember that aside from your total wattage requirements, you still need to add around 20% to account for any losses.
Conclusion
Installing a solar power system is a great idea if you want to stop relying on the grid for your electricity requirements. Thankfully, there are a variety of options available when it comes to solar systems. You need to calculate how many solar panels are required and work with a team of experts to install them properly. Once you do that, it will be easier to provide excellent results.
FAQs
Can I install solar panels on any roof?
You can install solar PV panels on most roof types. However, roofs with asbestos, thatch roofs, and glass roofs can’t really support PV panels adequately, so in these cases, PV panels are not recommended.
Do I need a battery for my solar system?
Most people don’t need a solar system with battery storage. However, if you want to store some energy for later when you might need it.
How long will it take to get a return on my solar investment?
It usually depends on the solar PV system you buy, how many panels it has, and so on. But on average, it’s expected to break even on your investment in roughly 6-7 years, maybe up to 9 years if we’re talking about a larger PV system!