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System Size

What size system will I need?

Choosing your system size isn’t always an easy task and there are many factors to consider. This is a main reason our knowledgeable energy consultants prefer to do a site visit and home consult in one, so we can discuss all the options with you and also make sure your meterbox is updated and has room for solar.

Let’s go through the main points to consider when choosing your system size:

Power Phase: Your home will either have single phase or three phase power coming from the grid. Single phase power homes only have one neutral wire and one power wire with current flowing through them. In a three phase system, there are three power wires carrying the load. To put it simply, if you have a single phase home, the largest system you can install will be a 5kW inverter with 6.6kW of solar panels. Three phase you have the capability of going larger than this with the repercussions of losing the feed in tariff (sending your excess power back to the grid and being paid for it by Western Power).

Power Consumption: How much you and your family usually consume when it comes to power, makes one of the largest impacts on what system size will be best for your home. We always suggest sitting down and looking through your last six power bills to truly gauge your usage over all four seasons. This is something we like to do at our home consults with you.

Roof Space: How much open space have you got to work with and is it a large open area or multiple arrays across your rooftop. If you don’t have a large north facing section of your roof, will you need to split your panels across the east and west? Splitting panels across multiples arrays may mean you need optimizers or micro-inverters to help your system function properly. Similarly, if you have a small or tricky rooftop, you may only be able to fit a 2-3kW system versus a 6.6kW.

Roof Pitch: This is a big one that a lot of people overlook. A steep pitched roof can make installation very difficult, and in some cases even impossible. This may mean on a multi pitched roof you can only install panels onto the lower pitched arrays. This can cut down how many panels can be installed, and thus your system size. If installation can be done, installers will need harnesses and rigging for any roof pitch over 30 degrees to comply with OH&S guidelines. This also occurs if your home is double storey or taller.

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