Challenging topography is no longer a barrier for utility-scale solar with Nextracker unveiling its game-changing single-axis tracker, writes Gavin Dennett.

A world of possibilities is opening for land that was once deemed off-limits for utility-scale solar plants. Thanks to new technology from Australia’s leading solar tracker manufacturer, Nextracker, sloping and undulating terrain that was considered impractical and too expensive for commercial PV farms can now be utilised.

Nextracker has recently unveiled its NX Horizon-XTR terrain-following, single-axis tracker that is designed for use on sites with sloped, uneven and challenging topography. The company began deployment and testing of the tracker three years ago, working with customers who faced capital expense and construction challenges on hilly project sites.

Land with these characteristics has historically introduced more risk and cost to projects, requiring significant earthworks and longer foundation pile lengths. However, the NX Horizon-XTR’s terrain-following capabilities can reduce grading, minimise steel costs and decrease project risk. It breaks the paradigm of the straight-line row design constraint by conforming to existing ups and downs of north-south ground slope undulations so trackers can follow natural site contours and no longer require installation along a single plane.

Nextracker Australia says the NX Horizon-XTR is changing utility-scale solar. Photo: Supplied.

“Historically, tracker rows needed to be built on a completely flat plain, and if the ground is undulating you need earthworks to flatten out the land, or use taller piers to counteract slopes in the ground surface,” Andrew Chino, sales director for Nextracker Australia, tells EcoGeneration.

“If the ground drops off, you’d either be filling it or flattening it, and with taller piers you’re using more steel. Also, once you get above about two metres in height, EPCs [engineering, procurement and construction] are working at height and they charge a premium, as well as there being more risk and difficulty with maintenance during the life of the project.

“Once you increasingly raise the tracker, wind loads on it increase and may have some structural impact. But the NX Horizon-XTR allows you to follow the contour of the land so you can mitigate earthworks – in some cases, 90 per cent of earthworks is removed – and make it a safer and easier installation.”

With 3GW of projects utilising this Nextracker technology already completed worldwide, it is a game-changer for utility-scale solar as the rapid expansion of off-grid projects, such as in mining, is happening in remote corners of Australia.

“Following feedback from our EPC partners in the US, the development of this technology came about out of necessity as projects moved to increasingly complex sites,” says Chino. “In Australia, we have an Indigenous heritage site under construction in Victoria where minimal intervention was necessary. Undertaking this project without NX Horizon-XTR would be impossible.

Andrew Chino from Nextracker Australia. Photo: Supplied.

“Another factor at remote sites is not only the cost of earthworks, but the expense to mobilise equipment. If it is a 5MW site that needs levelling, the cost is astronomical.”

In rural regions of Australia, where some utility-scale solar projects can be met with resistance from agricultural communities, there are wider ancillary benefits of the NX Horizon-XTR that may result in increased local acceptance.

“It is clear to see the benefits in terms of economics and preservation of land, but it also makes it easier for site owners to have conversations with council due to the reduced terrain impact of these developments,” says Chino. “Without the need for site earthworks, there are advantages with reduced erosion, dust mitigation, impact on waterways, and grass reseeding time for farmers who want to run their livestock on the land.

“It is opening possibilities for sites that would never have previously been considered. Renewable energy shouldn’t come at the cost of our environment, or be prohibited by cost. NX Horizon-XTR is a new frontier for solar developers to affordably build on sites that were once considered too expensive, while respecting the historical and environmental aspects of the land.”