Solar Innovations: Look Ma, No Rails!

An ambitious microgrid project in South Australia is chock-full of interesting features. One of them is a rooftop solar panel mounting system that doesn’t use rails.

Located 600 kilometres north of Adelaide in the northern Flinders Ranges, Arkaroola Wilderness Sanctuary was founded by the Sprigg family in 1968. Formerly a degraded sheep station, the 610sq km sanctuary is a haven for a wide variety of fauna and flora.

As well as its many natural attractions, Arkaroola Wilderness Sanctuary has accommodation, a restaurant and bar, shop, swimming pool and a service station.

Up until very recently, power for the sanctuary’s facilities has been provided exclusively by diesel gensets. But under the Australian Government’s Regional and Remote Communities Reliability Fund – Microgrids 2020-2021, funding was provided to trial and implement innovative renewable energy solutions. The trial has been led by Apex Energy Solutions.

Phase 1 of the microgrid project includes:

• 100kW of rooftop solar (Axitec solar panels) on the Mawson Lodge and workshop buildings ( expandable to 400kW).
• 121kWh CEGASA lithium-ion battery storage system ( expandable to 363kWh).
• 60kW continuous 3-phase battery Inverter/Charger (Selectronic – expandable to 180kW).
• Integration with the existing diesel generator system.
• A new main switchboard and underground cabling to major solar locations.
• A 22kW 3-phase public electric vehicle charging station.

There’s a really detailed write-up on the project from Apex Energy’s Sean LePoidevin here. Mr. LePoidevin is also the Regional Manager Australia and Pacific for Germany’s BOS Balance of Storage Systems AG.

Rail-Less Rooftop Solar

As you can imagine, there was a lot of gear that needed to be transported to the site, and over some less-than-ideal roads. Given the remoteness of the Sanctuary, a lot of thought also needed to be given to components as any failure could take quite a while to repair. This included the mounting system.

Usually solar mounting systems involve rails, on top of which the solar panels are fixed. For the Arkaroola project, S-5!’s¹ rail-less solution was used. Rail-less solar mounting isn’t new, but as far as I know isn’t commonly used in Australia.

In addition to significantly reducing the cost and complexity of transporting materials, S-5! claims their solution:

• Cut installation costs by 25% through eliminating the assembly and installation associated with conventional racking.
• Reduced dead load of mounting components by 750kg, placing less stress on the aging sub-structure.
• Increased system size by 7.3%, allowing freedom to install panels anywhere on the roof sheet.
• Completed solar installation approximately 37% faster than a conventional based rail-based mounting system.

“If you look at all the racking manufacturers out there, you still have one core problem – is that you’re a slave to a fixing point and a screw line,” says S-5! Product Trainer Bernie Dombroski. “You know, you really have to add more product and more weight into the roof. Where S-5! turns your roof into a canvas. You have no idea how liberating that is.”

S-5! says its system has been used for more than 2 million installations around the world, supporting 5.8 + GW of solar panels.