Why Landscape Solar Panels Can Be Better (But More Expensive)

Have you ever noticed that most solar panels installed on Australian roofs are mounted in portrait orientation?

Portrait is more popular because solar panels are cheaper and quicker to install this way.

This post will explain why panel orientation can matter, and why you may be better off with landscape panels despite the extra effort required to install them.

Note: This post is not about energy yield. In terms of energy yield, an unshaded portrait panel will generate the same as a landscape solar panel¹.

Solar Panels: Portrait Vs. Landscape

Imagine you want to put 11 solar panels on a typical Colorbond roof.

You could install them portrait like this:

Or landscape:

Is one orientation better than the other?

For the roof in the two images above, almost all installers will choose to install in portrait orientation. That’s because it is cheaper and quicker to install this way. In fact, a landscape install can take 50% longer.

Here’s why. With a portrait install, the installer will need to cut and mount 4 lengths of rail, and use 26 clamps to mount the panels:

For landscape, the installer needs to use 10 lengths of rail and 32 panel-clamps²:

So, with the extra effort required for a landscape install, why choose landscape at all?

The answer is space efficiency. On many roofs, landscape will let you mount more solar panels in the same space while still respecting their clamping zones and the roof’s exclusion zones.

This means you can get more energy from the same roof.

Here’s an example using the same roof as before.

WIth portrait orientation and respecting a 200mm exclusion zone around the roof-edge, we can fit 12 panels.

WIth landscape orientation, we can fit 15.

Extra kilowatts from landscape can be substantial

Let’s now look at an example on a full roof with some complicated roof faces.

With a portrait install, we can fit 47 panels³:

With a landscape install, we can fit 57. If they are 400 watt solar panels, that’s an extra 4 kW on the roof.

Rushed installers won’t install landscape solar panels

One of the problems with getting the cheapest quote is the installers don’t have the time or the inclination to install in landscape orientation.

To fit all the solar panels you’ve been sold on to your roof they may have to:

• force them to fit in portrait, violating either the panel clamping zones or the roof exclusion zones, or both.
• tell you you can’t have all the panels you’ve been promised because they won’t fit.

Imagine you’ve been quoted 15 panels for the roof below. If the salesperson has only looked at your roof on Google Maps, it will look like they will easily fit in portrait.

But here’s what can happen when the installer has been told to install them and is in a hurry:

This is the quickest and cheapest way for a rushed installer to install those 15 panels. Unfortunately, to squeeze them in, the installer has violated the 200mm exclusion zone that is generally required to meet AS 5033, the Australian Standard for solar installations.

The install is non-compliant, looks shit, and when it rains the water that hits the solar panels will likely pour off the bottom row like a little waterfall, missing your gutter altogether.

Also – if the roof’s existing screw-lines are not in a convenient position relative to the panels, you may have panel clamps in the wrong place, relative to the panel’s short edge – voiding the solar panel manufacturer’s warranty.

Be wary of salespeople who don’t consider landscape

Sometimes we’re asked for help by a consumer who has competing quotes outside of SolarQuotes where a salesperson is rubbishing their competition, claiming a competing quote has “more solar panels than will fit on your roof”.

Usually, this is because the accusing salesperson has not considered landscape orientation⁴.

All-electric future makes landscape solar panels more important

The future of residential energy in Australia is all-electric. In the near future, most homes will have electric heating, electric cooking, electric water heating, batteries, and an electric car or three. To power all that stuff, you’ll want to fill your roof with solar. Depending on your roof shape, this will often mean landscape solar is the best choice. Just don’t expect one of the big cheap retailers to offer it as an option.

Endnote: How to compare a landscape vs portrait solar panel layout in 2 minutes

I made the images in this post with SketchUp and the Skelion extension. If you have an accurate scale model of your home⁵, you can fit landscape or portrait solar panels on your roof in 2 minutes like this:

1. Use the ‘offset’ tool to create a 200mm exclusion zone inside the roof edges.
2. Select the roof areas.
3. Hit the Skelion ‘add panels’ button
4. Tell Skelion if you want portrait or landscape orientation.
5. Done!

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Original Source: https://www.solarquotes.com.au/blog/landscape-solar-panels/