Most 3-bedroom Newcastle homes need a 6.6kW to 10kW solar system, which is roughly 15 to 24 panels on the roof. Installed, that lands somewhere between $5,500 and $11,000 after the federal STC rebate, depending on panel quality, the inverter and how tricky your roof is.

That's the short answer. The right number for your place depends on how much power you use, when you use it, and what your roof can actually fit. Here's how we work it out on a real quote.

Start with your actual usage, not a rule of thumb

A typical 3-bedroom home in Charlestown or Merewether uses somewhere between 15 and 25kWh a day. Pull out a recent electricity bill and look for the average daily usage in kWh. That single number tells us more than the number of bedrooms ever will.

As a rough guide, every 1kW of panels produces around 4kWh a day averaged across a Newcastle year. So a 6.6kW system makes about 26kWh on a good day and closer to 15kWh in a wet July. A 10kW system will comfortably cover a family with air-con, a pool pump and an EV starting to appear in the driveway.

If your usage is mostly daytime — someone home during the day, or you run the dishwasher and washing machine while the sun's up — a bigger system pays for itself faster. If everyone's out until 6pm, the sums change, and that's where a battery starts to make sense.

Why we push most homes to 6.6kW or bigger

Feed-in tariffs have fallen hard. You're now looking at 4 to 7 cents per kWh for power you export to the grid, while you're paying 30 cents or more to buy it back. So the value is in self-consumption — using your own solar rather than selling it cheap.

That's exactly why we rarely recommend going small to "match the bill". Panels are the cheapest part of the whole job. Once the installer is on your roof, the labour, rails and inverter cost much the same whether you fit 15 panels or 22. Adding a few extra panels is cheap headroom for future air-con, a heat pump hot water system or an EV.

A 6.6kW system paired with a 5kW inverter is the most common setup we install, largely because it maximises the STC rebate against a modest inverter cost. Step up to a 10kW array with an 8 to 10kW inverter if your roof and budget allow.

What we actually check when we visit

Roof space and orientation come first. A north-facing roof is ideal, but split east–west arrays often suit families better because they spread generation across morning and afternoon. In Newcastle we also watch for the salt-air exposure closer to the coast, which is why we spec quality mounting hardware.

The switchboard is where a lot of quotes come unstuck. Older Newcastle homes — plenty of them from the 60s and 70s — often have a board with no room for the required solar isolator and breaker, or old ceramic fuses. If that's your place, budget an extra $800 to $1,500 for a switchboard upgrade. A cheap quote that ignores this isn't cheaper; it's incomplete.

We also check your meter. Most Ausgrid-area homes will need the meter reconfigured or swapped to a bi-directional import/export meter before the system can be switched on, and that's arranged through your retailer. It's a common surprise, so we flag it upfront rather than at the end.

One mistake we see repeatedly on other installers' work: panels crammed too close to the ridge or valley with no clearance, or strings running under a whirlybird or antenna shadow. Shading from one chimney can drag down a whole string if the panels aren't laid out and wired properly. Layout matters as much as the gear.

Do you need a battery too?

For an evening-heavy household, a battery lets you store cheap daytime solar and use it at night instead of buying at peak rates. The NSW battery incentive currently knocks a decent chunk off the upfront cost, and combined with the federal rebate on the panels, the numbers are far better than they were two years ago.

Our honest take: get the solar sizing right first. If you go to 10kW of panels now, you can add a battery later without touching the array. Oversizing the panels slightly is the easiest way to make a future battery worthwhile, because you'll have surplus generation to store rather than export for 5 cents.

Get a straight answer for your roof

Every 3-bedroom home is a bit different — the roof, the switchboard, the usage pattern and whether an EV or pool is on the horizon. We'll look at a recent bill, measure your roof and give you a fixed-price quote with the panel count and inverter spelled out, plus any switchboard or metering work included rather than hidden.

Book a free on-site assessment with Impressive Electrical & Solar and we'll size the system properly the first time.