Shading of Solar Panels in an Array

Placement of Solar Panels

If you want to place a solar array behind another array, you would need to ascertain whether the front array will cast a shadow on the rear array.

There is a trigonometric formula to calculate how far the shadow of the front array will be cast at midday during the winter solstice.
Winter of course is when the shadow is the longest and longer in the morning and afternoon than at midday.
But to calculate the length of the shadow at any time of day and from that to calculate how far behind the front array you need to be gets very complicated, mathematically speaking.

You would need to calculate how far south (in the southern hemisphere) the eastern corner of the front array casts on the rear array in the morning and how far south the western corner of the front array casts on the rear array in the afternoon, taking the width and placement of both arrays into consideration.

To help to figure this out, we have produced a series of tables covering latitudes from the northernmost tip of Queensland down to Tasmania.

How - NOT - to

Having a row of cells shaded will reduce the power output significantly.

sketch of solar array casting shade on array behind


Here's an illustration to help you understand the tables.

Winter Shadow Digram

Effect of Shade

The demonstration "Effect of Shade on Solar Panels" was developed and is hosted by Barry Miller.

We install solar systems in Northern NSW and Southern QLD.

Gold Coast (from Coolangatta to Southport), Nerang and Hinterland (Beaudesert) and out West (Warwick, Stanthorpe, Killarney)

Northern NSW (Tweed Heads to Yamba, including Evans Head, Byron Bay and Ballina); the Far North Coast Hinterland (Grafton via Lismore to Murwillumbah) and out West (Casino to Tenterfield, including Drake and Tabulam, as well as Woodenbong and Bonalbo)

For larger system we also go up to Brisbane or down to Coffs Harbour and even Glen Innes. Other places by arrangement.

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Rainbow Power Company would like to assure our customers that we are trading (not quite as normal). System designers are working from home and can customise a quote for you (free of charge) over the phone and online. We are still dispatching and posting items, with safety precautions in place. You can still order online or over the phone, and pick up items from RPC (our show room is closed however, and appointments must be made to pick up orders). We are still doing site inspections, keeping the recommended social distancing.

Contact us

This is the perfect time to start thinking about your power needs for the future, reducing your bills, and safeguarding against future power outages, so call today and get in before the oncoming solar rush. PH: 02 6689 1430 or send an enquiry
..stay safe and healthy, your RPC family