What size solar system does a Bendigo home need?

Start with your electricity bill

Your power bill is the best place to begin. Look for your average daily use, shown in kilowatt-hours (kWh). This is the total electricity you used divided by the number of days in the billing period. The government's Solar Consumer Guide notes that Australian homes use roughly 11 to 23 kWh a day on average, but every household is different.

It is worth checking a summer bill and a winter bill, because many homes use quite different amounts across the year. If you have a smart meter, you can ask your electricity distributor for your interval data, which shows exactly when you use power through the day. That detail helps match a system to the way your household actually lives.

What system size actually means

The size of a solar system is the combined capacity of all the panels, measured in kilowatts (kW). For example, 19 panels rated at 350 watts each add up to 6.65 kW. The inverter, which turns the power from your panels into power your home can use, is often sized a little smaller than the panels, because panels rarely produce their full rated output.

Inverter sizing has rules attached. If the panel capacity goes beyond what the inverter manufacturer allows, the system may not be eligible for the federal STC discount. This is one of the reasons it pays to have a qualified installer design the system rather than picking a number off a website.

Your roof and when you use power

Sunny roof space is often the deciding factor. Panels work best on roof areas that get good sun through the middle of the day with little shade from trees, chimneys or neighbouring buildings. In Bendigo, north-facing roofs are usually the most productive, while east and west-facing roofs can still work well and spread your solar output across the morning and afternoon.

When you use electricity matters as much as how much. Solar saves you the most when you use the power yourself as it is generated, rather than sending it to the grid. If your home is busy during the day, or you can run things like the dishwasher, washing machine and pool pump while the sun is out, you will get more value from each panel.

Think about the next 20 years

A solar system can last 20 years or more, so it makes sense to size it for the life you expect to be living, not just today. Plenty of Bendigo households are adding air conditioning, switching from gas to electric hot water, cooking or heating, or planning for an electric vehicle. Each of these can add noticeably to your electricity use.

If a battery might be on the cards later, mention it when you get a quote. Choosing a suitable inverter and leaving room on your switchboard now can make adding a battery simpler down the track. It is also worth knowing that your electricity distributor may limit how much power a system can export to the grid, which can affect the best size for your home.

Getting a size you can trust

Free tools like the government-backed SunSPOT calculator can give you a useful ballpark figure before you talk to anyone. Have a recent bill handy to make the estimate more accurate. Solar businesses then use specialist design software, and it is fair to ask what assumptions sit behind any savings estimate they give you.

The most reliable recommendation comes from someone who has looked at your bills, your roof and your switchboard. As licensed electricians with more than 30 years in Bendigo, we are always happy to talk you through the options and explain why a particular size suits your home.

Next steps

Want help with this at your place? See our Solar Panels and Solar Upgrades pages, or start with Solar Installers Bendigo for an overview of how we work across Bendigo and surrounds.