Solar panels across Macarthur

Macarthur is not one housing market. Campbelltown's suburbs were built over several decades, so the switchboard and the roof type are the two things that move a quote. Around Camden's town centre many homes are older, with terracotta roofs that need careful walking and flashing, and a heritage conservation area over some streets.

The estates around Oran Park, Harrington Park, Spring Farm and Mount Annan are the opposite: modern switchboards, metal roofs and often a three-phase supply. Installs there are usually simple. The real decision is size, because many of these homes already have a small system on the roof that was never meant to cover the household that moved in.

Inland Sydney has markedly more very hot days than the coast, and on most estate bills ducted cooling is the biggest single load. It runs in the middle of the day, which is when panels generate, so a larger system covers more of it. A 6.6kW system covers part of a hot afternoon with the house full. For bills driven by summer cooling, 10kW or more is usually the sensible starting point.

Two other loads change the answer here more than anywhere else in Sydney. A pool pump is the most flexible load in the house, and timing it into daylight is free. An electric car needs fewer extra panels than people assume, but only helps if it is plugged in while the sun is up. We size from a summer bill and your plans, not from the roof area.

A new NSW home has to meet the BASIX energy standard before it is approved, and a small rooftop system is one of the cheaper ways for a builder to meet it. That is why so many estate roofs carry a modest system with a budget inverter. It was built to pass an assessment, not to cover your bill.

There are three ways to grow it: add panels to the existing inverter if it has headroom, add a second inverter and array beside it, or replace the inverter and reuse the panels. Which is cheapest depends on the inverter already there. Any added capacity counts as an upgrade, so it needs a fresh connection application under the rules in force on the day you apply.

Every suburb page in this region sits on the same distribution network, so the export rules are the same from Campbelltown to Oran Park. On a flexible export connection, eligible customers can export up to 10kW per phase most of the time, with the inverter easing back when the local network needs it. If you choose a fixed limit instead, exports are capped at 1.5kW.

From November 2026 flexible exports become the default for eligible new and upgraded systems. Eligibility needs an active internet connection and an approved inverter, so plan for both. Many older Camden and Campbelltown homes are single-phase, which makes 10kW the whole allowance. Estate homes on three phases get it per phase, which leaves room for a much larger system.

The NSW Emergency Backstop Mechanism lets the network reduce or pause rooftop solar exports during rare grid emergencies. On this region's network it is being phased in by postcode from late 2026, and all new and upgrading systems up to 200kW must be backstop-enabled by 30 April 2027. Day to day you would not notice it, and it does not stop your system supplying your own home.

Systems already on the roof are not affected. If you are adding to a builder's system or replacing an inverter, the upgrade brings it under the new requirement, so the equipment has to be compatible. We build every new system and every upgrade to meet the rules in force when it is installed.

Mount Annan and parts of the surrounding estates are built across hills, so roofs face every direction. An east and west split makes less at noon than a north array but more in the morning and late afternoon, when most households use power. Hills can also shade a roof in winter, when the sun is low, so we check the winter sun path rather than the summer one.

Rooftop solar on a house is usually exempt development. The exceptions are Camden's heritage streets, where panels visible from the street can need approval and a rear roof face is the usual fix, and estate design covenants, which are private agreements separate from council. Acreage out towards Cobbitty and Grasmere often suits a bigger system, with the cable run as the cost to watch.