Solar panels across the Hills District

The older Hills suburbs, Baulkham Hills, Castle Hill, West Pennant Hills and Cherrybrook, are large established homes on leafy blocks. Expect two-storey access, tile roofs that need careful flashing, mature trees that shade a roof in winter, and often a switchboard upgrade. Many of these roofs already carry a small system from the early 2010s.

Rouse Hill, Kellyville Ridge and the estates around them are newer, usually with modern switchboards and, more often than the Sydney average, a three-phase supply. Installs there are simpler. The question we hear most is whether the next dollar should go on more panels or a battery, and the answer is usually panels first until the roof is full.

Most of the region is on one distribution network, but the boundary with another runs close to Cherrybrook, and neighbouring suburbs are not all on the same one. Flexible exports of up to 10kW per phase are common to both. The fixed-connection figure is not: one network caps a fixed connection at 1.5kW, the other approves 3kW.

The NSW Emergency Backstop Mechanism also runs to different timetables. Both phase it in by postcode from late 2026, but one requires every new and upgrading system to be backstop-enabled by 22 February 2027 and the other by 30 April 2027. Existing systems are not affected on either. We confirm the rules for your actual address and put the limit in writing before install day.

Plenty of Hills roofs still carry a 1.5 to 3kW system installed while the NSW Solar Bonus Scheme paid a gross feed-in tariff. That scheme closed on 31 December 2016, so those systems now earn an ordinary retailer rate. Upgrading cannot cost you a tariff you no longer receive.

What you gain is capacity: a modern system on the same roof generates several times as much. A replacement counts as an upgrade, so it comes under the current export rules and the backstop requirement. If the old inverter has failed but the panels are sound, a repair can still be the better answer, and we will give you both numbers.

Large Hills homes often run ducted zones, a pool and two cars, and much of that load lands in the evening. That is why batteries come up in nearly every quote here. A battery earns on the gap between what you pay for a kWh and what you are paid to export one, which is real but bounded. Panels added while the installer is already on the roof are cheaper per kWh.

A battery quote often arrives with a virtual power plant bonus attached. The bonus is usually paid once while the commitment runs for years, and during an event the operator decides when your battery discharges. Read the reserve and exit terms before you sign, especially if outage backup is part of the reason you want a battery.

Townhouse and strata schemes have gone up along the Metro corridor, around Castle Hill in particular. In most schemes the roof is common property, so a lot owner needs the owners corporation's approval, usually by resolution and a by-law covering maintenance. That approval is separate from council and from the network's connection approval, and neither stands in for the other.

Norwest adds offices, medical suites and showrooms. Their load runs to the same clock as the sun, so little is exported, but a leased tenancy rarely controls its own roof. The building owner, the owners corporation or a negotiated lease clause are the usual paths, and commercial connections are assessed individually.

Rooftop solar on a house is usually exempt development whichever council you are in. Council does matter for heritage listings and for tree removal, which is a live question on the leafy blocks of West Pennant Hills and Cherrybrook, and the councils' rules differ. West Pennant Hills is split between The Hills and Hornsby, Rouse Hill between Blacktown and The Hills, and parts of Winston Hills sit in the City of Parramatta.

Where the roof allows, we put the array on a rear or side face. If the only worthwhile sun is on the front, we show you the layout and the difference in output before you decide.