Solar Panels and Shading: What to Do If Your Roof Isn't Perfect

Shading is the single biggest performance killer for rooftop solar — but it doesn't disqualify your home from going solar. With modern panel technology, microinverters or DC optimisers, and intelligent system layout, even partially shaded Illawarra roofs can produce 80–95% of an unshaded system's output. The trick is knowing where the shade falls, when, and choosing the right hardware to deal with it.

Why shading hurts solar so much

Solar panels are wired together in strings. On a traditional string inverter setup, the entire string flows through whichever panel is producing least — like a kink in a hose. Shade just one cell of one panel, and the current available to the whole string collapses to match. This is why a single chimney shadow at 9am can cost you 30% of your morning generation.

Modern panels mitigate this with bypass diodes that route current around shaded sections, but the protection isn't complete. The deeper fix is to give every panel its own electronics so each one operates at its own maximum power point — which is exactly what microinverters and DC optimisers do.

Common sources of shading on Illawarra roofs

Across the 1,200+ Illawarra installs we've assessed, the most common shading culprits are:

• The Illawarra escarpment: Homes on the lower slopes of Mount Keira, Mount Kembla and the Bulli/Coalcliff strip lose afternoon sun earlier than coastal homes. We typically see 30–60 minutes of effective generation lost from 3pm onward in winter.
• Tall trees: Eucalyptus and Norfolk pines along the coast cast long, moving shadows. Even branches that look "thin" can drop output 20%+ when they sweep across panels in wind.
• Chimneys, flues and vents: Small obstructions cast surprisingly large shadows in low-angle morning and afternoon sun. Solar hot water tanks on the roof are a classic offender.
• Neighbouring buildings: Two-storey homes built close on the north or west side can shadow your roof for 2–3 hours daily. Common in older Wollongong suburbs like Mangerton, Mount Pleasant and West Wollongong where lots are tight.
• TV antennas and satellite dishes: Often forgotten in early planning, but they cast narrow shadows that walk across panels through the day.
• Gable walls and dormers: Self-shading from the home's own roof geometry — common on cottage-style and federation homes around Thirroul and Austinmer.

How to assess your roof's shade in 5 minutes

You don't need fancy software to get a rough read on shade. Walk outside three times on a clear day — at 9am, midday and 3pm — and look at your roof from the ground or a window. If panels would go where there's full sun at all three times, you're golden. If the 9am and 3pm checks show shade creeping across, that's where DC optimisers or microinverters earn their keep.

For a more rigorous assessment, your installer should do a Solar Pathfinder reading or use a drone/Google Sketchup model to simulate sun paths through every season. Reputable installers — including ourselves — do this as part of every site assessment, not just on visibly tricky roofs.

String inverters vs microinverters vs DC optimisers

Three inverter architectures exist, and the right choice depends on your shade situation, budget and roof complexity.

String inverter (the budget option)

One central inverter (typically Sungrow, Fronius or GoodWe in 2026) handles all panels wired in series. Cheapest option, most common in standard Illawarra installs without shade issues. Performs poorly under partial shading. Best for: simple, unshaded north-facing roofs.

DC optimisers (the middle ground)

SolarEdge is the dominant brand here. Each panel gets a small electronic device that lets it operate at its own maximum power point, fed into a central inverter. Adds roughly $800–$1,500 to a 6.6kW system, but recovers 15–25% of generation on partially shaded roofs. Includes per-panel monitoring. Best for: multi-orientation roofs, partial shading, complex layouts.

Microinverters (the premium option)

Enphase is the only serious player. Each panel has its own dedicated micro-inverter on the back, converting DC to AC at the panel itself. Eliminates string losses entirely, offers the best monitoring and is the safest option in fire risk areas (no high-voltage DC on the roof). Adds $1,500–$2,500 to a 6.6kW system. Best for: heavily shaded roofs, multi-aspect designs, bushfire-prone properties, owners who want maximum future-proofing.

Use our free Solar Savings Calculator to see your personalised payback period.

Should you trim or remove trees?

This is one of the trickier conversations we have. Sometimes the cheapest, best fix is to trim or remove a problem tree — but Wollongong City Council and Shoalhaven City Council both have tree preservation orders that protect significant trees, and removal without permission can attract fines of $1,000+ per tree. Before any trimming or removal:

• Check your council's vegetation/tree register (Wollongong's is searchable online)
• Identify whether the tree is on private or council land
• For trees over 5m tall or with a trunk diameter over 300mm, you'll likely need a permit
• Get an arborist's report if you're applying for removal — councils want this

In many cases, professional pruning to lift a canopy or thin foliage is sufficient and doesn't require council permission. We can recommend Illawarra arborists we work with regularly.

Layout strategies for shaded roofs

Even on imperfect roofs, smart layout choices recover most of the loss:

• Split the array across multiple roof faces: A 10kW system might be 5kW on the north face and 5kW on the west — losing only 5–8% generation while completely sidestepping a north-side chimney shadow.
• Skip the shaded zone entirely: Sometimes the right answer is to install fewer panels in the unshaded sections rather than fight a losing battle in the shaded ones.
• Use east-west layouts to flatten the production curve: Better for self-consumption matching with morning showers and evening cooking, and avoids midday shading from a single tree to the north.
• Consider 440W+ high-efficiency panels: Brands like REC Alpha Pure, LG NeON H, and Jinko Tiger Neo recover better from partial shading than budget panels because of advanced cell architecture.

Frequently Asked Questions

My roof is east-west facing — can I still go solar?

Absolutely, and tens of thousands of NSW homes do. East-west splits produce 10–15% less annual generation than a pure north-facing array but match daytime usage patterns better, which often makes them more financially valuable. Self-consumption beats export in 2026's feed-in tariff environment.

How much production will I lose to shade?

It depends on the shade timing and severity. As a rough guide: morning shade until 9am or afternoon shade after 3pm typically costs 5–10% annual production. All-day partial shading from a tree directly to the north can cost 25–40%. We'll model your specific situation in your free site assessment.

Are microinverters always better than string inverters?

No — for a simple, unshaded north-facing roof, a quality string inverter (Sungrow, Fronius) gives near-identical output at significantly lower cost. Microinverters earn their premium specifically when shade, multiple orientations, or future expansion are factors. We don't recommend the upgrade where it isn't needed.

Will my neighbour's tree get my system rejected by Endeavour Energy?

No — Endeavour Energy approves grid connections based on electrical compliance, not generation expectations. Shade affects how much you'll save, not whether the system can be installed. The tree concern is purely an economic one that you weigh during sizing.

Can I add panels later if I trim shading trees?

Yes, provided your inverter has spare capacity and you stay within Endeavour Energy's connection limits. We typically size inverters with 1–2kW of spare DC headroom for exactly this scenario — it's much cheaper to add panels to an existing system than to upgrade the inverter later.

Ready to get your personalised quote? Contact our CEC-accredited team — we'll call you back within 5 minutes.