Australia has the highest rate of residential solar power installations in the world. Their system sizes and their number of panels vary from one to another as electricity needs and condition differ. Most of the residential solar installations range from 2kW to 5kW systems but there are a lot of factors to consider. We have listed here the 3 main ones:
- Your electricity needs
First of all, you need to analyse your electricity bill and find out your total consumption during the billing period. You easily get your daily consumption by dividing the total consumption by the period. Then, the rule of thumb is to divide the daily kWh per day by 4 (4kWh/kW in Victoria) to get the system size you need.
For example, if your peak usage is 360kWh per month, then your daily consumption is 12kWh (360kWh/30). The system you need is 12kWh/4, which is a 3kW system.
A 3kW system consists of 3kW solar panels (normally 12x250W), a 3kW solar inverter, a racking system for mounting the panels, electrical switchgear for protection and others necessary components and labels.
You can also have a look at your highest demand. Not all electricity retailers show the highest demand on their bill but if you can find such component, considering the losses of the panels, inverters and cables, the system size you need is basically slightly higher than your demand for peak offset.
For example, if your highest demand during a period is 3.8kW, the system size you need is 5kW. *
* Disclaimer: The above calculation is approximate, however, there are a lot of factors to be considered to design a proper system. Contact us to find out more.
You can also identify the system you need from the below table:
When do you use your electricity?
Solar panels produce electricity only during daytime hours. The electricity should be used as it is produced or it will be feed to the grid. The feed-in tariff is lower than what you pay for electricity which means it is better to use your generated electricity than sending it to the grid.
You can determine your daytime consumption by reading your meter in the morning and in the evening. Ideally, your solar system covers at least your daytime consumption.
You can also add batteries storage to your solar system. The power produced during the day and not consumed will be stored for later usage, at night or when the production is lower than your electricity needs. Wherever you need energy storage or not depends on your objectives, your electricity usage and your daily production.
- The size of your roof
The size of your roof is also something to consider. It will determine how many solar panels can fit. You need to find out how much of your roof space is suitable for panels depending on its orientation and shade coverage. Panels can be installed in any kind of roof, both in portrait and landscape position but they must be directly facing the sun and shouldn’t be installed on a south-facing roof. Shade will also affect the performance of the panels. If your roof is covered by shade from trees, power poles or chimneys for instance the performance of your panels and so your production will be reduced.
- Your Budget
How much you can afford to pay and your saving expectations will definitely influence the system size and the number of panels of your system.
However, different funding options are available for residential installations and government incentives significantly lower the price of solar.
This information is a guide only and there a lot of factors to consider to design a solar power system. Contact our team of professionals to find the right system for your home call 1300 782 217 or send your electricity bills to ea@energis.com.au
