What size solar system do I need

What Size Solar Do I Need? A Simple 7-Step Guide

As the climate change conversations get louder and more urgent and power bills continue to escalate, the appeal of getting solar panels installed is obvious. But while the decision to make the switch to solar energy might be obvious, much less clear is choosing the right path to the installation you need and want. It’s not about a specific brand, colour, style or even headline solar system sizes. Rather, it’s about understanding exactly what you want from your solar panels.

Most homeowners simply want to harness the sun’s free energy to meet all of their electricity needs – because imagine just how frustrating it would be to spend all that money and go through the process of getting a solar system installed only to discover that it’s inadequately sized to meet the energy needs of the household. So, as you begin your solar journey, we pose and answer the question for you: “What size solar system do I need?”:

How many Kw solar do I need? A beginner’s guide

How much solar do I need? Before we get to that, there would be an awful lot of technical jargon and details that would make determining the right solar system size super-daunting. So let’s break it down into simple steps with our straightforward guide to answering that straightforward question in your head: How big a solar system do I need?

1. Figure out your current energy usage

How much energy will you need from your solar system? Figuring out how to calculate solar system size can seem overwhelming, but it doesn’t have to be. For instance, just take a look at your latest electricity bill. How many kilowatt-hours (kWh) have you used? Turn it into a monthly average, and then look only at solar systems capable of producing it. Easy, right?

2. Figure out the sunlight exposure

A little more difficult is researching the average sunlight hours your proposed solar location will receive every day – with a focus on peak sunlight hours, as that’s when solar is best at cranking out the watts! No idea how? Look up the online solar insolation map for your area (Google it) and it will tell you how many kilowatt-hours of solar energy fall on a square metre of ground in an average day over a month where you are.

3. Understand the baseline

Although individual solar setups vary in terms of efficiency, an average panel produces about 300 watts per hour in optimal conditions. That’s your baseline for determining what size solar system will best suit your needs.

4. Calculate your system size

Now, divide your particular average monthly kWh by 30 to get the daily kWh needs that you’ll require for your setup. Then, divide this number by your location’s daily peak sunlight hours and what you’ll get is the required system size in kilowatts, considering the solar panel size that is most appropriate for your needs.

5. Don’t forget about efficiency losses

You’ll need to factor in about 25% for efficiency losses – which is due to energy lost through wiring, your inverter processes, unpredictable shading, and the fact that your panels need to be angled towards the sun with meticulous detail. To understand your losses, multiply the system size by 1.25.

6. What will change in the future?

It’s possible, and likely, that your energy consumption will change at some point in the future. For instance, in 5-10 years, it is extraordinarily likely that you’ll upgrade to an electric car – and that’s going to change everything!

7. Seek professional advice

Before taking our advice from steps 1-6 and making arrangements for your new solar setup, make sure to really do your homework by consulting with an experienced solar energy professional. They’ll help validate your rough calculations and ensure you haven’t overlooked anything.

Ask a Pro: How much solar do I need for my house?

You’re now armed with the basic knowledge you need to embark on your solar energy adventure. But the real road to solar success requires more than just a DIY spirit – so before finalising your plans, consult with the seasoned experts at Solar Repair Sydney. They’ll refine your calculations, pinpoint the oversights, and provide tailored advice as well as ongoing support, maintenance and repair services so that you’ll not only install the perfect solar system for your needs but also ensure its long-lasting performance. Don’t leave your solar dreams to chance and instead connect with Solar Repair Sydney.


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