The team at Solar WA are often asked really insightful questions when a customer is looking to make the switch to solar for their homes. A question we get time and time again is “What Sized Solar Energy System Do I need For My Home?”.

Today we want to address this, explaining how we can accurately calculate the number of solar panels required that will meet your adequate usage and give you that return on investment you will want to see from your solar energy system. After all the majority of people who invest in a solar energy system for their home do so to lower energy consumption and their energy bills.

So where do we start? The best place to start is always with your current consumption and energy usage.


Review Your Last 3 Month’s Energy Bill

Yes this really is the place we start! If you can review your recent energy consumption and come up with an average figure, then we will know how much energy a solar energy system needs to generate. It is often advisable to calculate this number in the summer months because in Perth and Western Australia, this is when the air conditioning systems are in full swing and generally, when energy consumption is at its highest.


Calculate Daytime Consumption

A key point to remember is that a solar energy system will only deliver energy during daylight hours. As soon as the sun goes in, you will be back on the grid, which is not ideal especially if you have excess energy from too much sun light. That’s where a battery storage system comes in very handy. With that said, you still do get the most out of your solar panels when the energy is used directly during the day as you reduce the demand needed from your electricity retailer.

By calculating your daytime energy consumption, you can estimate far more accurately what sized energy system you will need. If you see that your energy bills are much higher than your daytime consumption, then a battery storage solution may be in order.


Meet The Daytime Demand

We will often recommend a solar energy system that will meet the daytime demand of the household, without the need for a battery storage solution. A few factors need to be taken into account on the lifestyle of the occupants of your home. For example are people home during the day in the week as this will impact consumption quite dramatically and could be the difference between a 2 kWh solar energy system and a 3 kWh solar energy system.

If we go off what we call an average Australian four bedroom home, with an average sized family that uses air conditioning, television, appliances fairly often, we would expect the daily energy consumption to come in around 14 kWh to 18 kWh (kilowatt hours). From here we can give a breakdown of what solar energy we need to generate.

Typically speaking a 1kWh solar energy system will generate 5 kWh of energy per day, which gives you quite a clear way of calculating what size of solar energy system you will need. Where you are in Australia will be important in this calculation as the weather varies from coast to coast. Perth homes are in a prime location to go solar, which is why 2017 has been a major year with homeowners switching to solar.

As you can see a lot of the calculations are data driven estimates. Coupled with the extensive experience the team has at Solar WA, we tend to have great insights into what size of a solar energy system a typical Perth home requires. Furthermore our friendly team of solar experts will give you this advice for free and can help you make the decision as to what size of solar energy system you will require.