Sizing · 3 min read · 1 October 2026
Is an East-West Roof Good for Solar Panels?
East-west roofs make less at noon but spread solar across the morning and afternoon. Here is when that suits a home, and what to watch for.
Read article →Sizing · 3 min read
How Much Does Shade Affect Solar Panels?
Quick answer
Shade affects solar more than most people expect, because panels are wired in groups and a shaded panel can hold back the others in its group. Good design avoids the worst of it: placing panels away from shade, splitting groups across inverter inputs, and using optimisers where shade can't be avoided.
Why does a small shadow make a big difference?
Panels are usually wired together in a string. Power flows through the string like water through a hose: if one panel is shaded, it can restrict the flow for the whole string. Panels have built-in bypass diodes that let current skip around shaded sections, which limits the damage, but a shadow across part of a string can still cost far more than the shaded area suggests.
What kinds of shade matter?
- Trees. They grow, so shade gets worse over the years.
- Neighbouring buildings and second storeys. Especially in winter, when the sun is low.
- Roof features. Chimneys, vents, aerials and dormers cast moving shadows.
- Dirt and debris. Leaves and bird droppings act like small, permanent shadows.
How do installers design around shade?
- Place panels where the sun is. Leave shaded corners empty rather than filling every space.
- Group panels by shade. Panels with similar shade go on the same string, ideally on a separate inverter input.
- Use more than one roof face. East and west faces can avoid a shaded north face.
- Add optimisers where needed. Panel-level optimisers or microinverters let each panel produce on its own.
How can I tell if shade is costing me?
Check your inverter app on clear days. A dip at the same time every day often lines up with a shadow passing over the panels. Seasonal changes are normal as the sun moves, but a growing dip over months often means a tree is getting taller.
A real example
We installed 7.6 kW of Jinko panels with a 49 kWh GoodWe battery in Turramurra. The upper North Shore has some of Sydney's tallest trees, so on homes there we look at where shadows fall through the day before deciding where the panels go and how they are grouped.
What we do at the inspection
We check every roof face for shade at different times of day and design around it. If shade means a system won't perform well, we say so plainly.
Related project
A real Panda Power install that shows this topic in practice.
What it costs
Home batteries from $6,999 to about $15,999
base prices after rebates, inc GST, as at October 2026
What affects the price: battery size, brand and inverter, whether you already have solar, backup wiring, and any additional work at your home.
Base price for a standard install, after government rebates, inc GST, as at October 2026. Additional work such as switchboard upgrades, three-phase changes or complex installs is reviewed and quoted separately.
FAQs
Will a little shade in the morning matter?
Usually only a little. Shade early or late in the day, when output is low anyway, costs less than shade around midday. The time of day the shade falls matters as much as how much shade there is.
Do optimisers or microinverters fix shading?
They reduce the loss by letting each panel work on its own, so one shaded panel doesn't drag down the rest. They add cost, so they are worth it only where shade can't be designed around.
Should I cut down trees for solar?
That's your call and may need council approval. Often trimming, or placing panels on a less shaded face, is enough.
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Install before 1 January 2027