Building PV systems on landfills using root systems

The limits of conventional driven piles

Conventional mounting systems, which are pile.drived into the ground usually involve going to depths of 1,5 to 2,5 meters. On recultivated landfills, where a sealing film is located about 60-80 cm below the surface, conventional piles cannot be used without risking damage to this crucial barrier. The layer of soil on the geomembrane may not be unified and the conditions of the groundwater may also present a chalenge that can influence the stability of conventional piles. Additionally, conversion areas, such as former industrial sites, often contain underground obstacles like old foundations, pipes, or debris that make traditional piling techniques infeasible. In these cases, specialized shallow-depth systems like those offered by TreeSystem, Form-Tec, and Corab are necessary to safely and effectively install solar panels.

An overview of root systems

The system gets its name from its similarity to tree root anchoring systems, providing stability to the structure. All root systems utilize shallow foundations that distribute the load across the surface, ensuring stability without compromising the landfill's integrity. The installation process is simple and safe, requiring only a handheld rammer, avoiding the need for heavy machinery like drilling rigs. This approach reduces risks, such as sparks or potential gas explosions from trapped landfill gases, and maintains the site's safety and stability.

There are several manufacturers of this type of mounting system, and our Greenbuddies installation Teams have worked or are planning projects with most of them, including:

TreeSystem

TreeSystem is an Italian company, specializing in the production of this type of PV system. The company produces single-pitched structures, as well as double-pitched for east-west orientation, all to be used where conventional mounting systems cannot be used.

Form-Tec

Form-Tec is a renowned German PV mounting system manufacturer, based in Bremen, which produces various types of PV mounting systems, conventional ground-mounted systems, systems for Agri-PV, carport structures and also root systems for slopes and landfills.

Corab

Corab is a leading Polish manufacturer of photovoltaic systems and distributor of devices of renowned brands, with a focus of the production of steel and aluminum products. Their variety of products includes PV systems for ground-mounted solar plants, rooftops, Agri-PV vertical and slanted, carports and root systems.

Greenbuddies' Experience with root systems

Greenbuddies has extensive experience implementing root-based mounting systems across Europe, particularly in challenging environments like landfills.

The first three solar plants using TreeSystem that our teams worked on included a 750 kWp installation in Reesberg, Germany, and two projects in Malta—Siggiewi (0.84 MWp) and Kornelio, a 5.2 MWp power plant with 14,280 modules installed on a former landfill.

In Sweden, we recently completed two projects with a combined capacity of 8.3 MWp, demonstrating the system's ability to handle complex installations. Another previously mentioned project in Halmstad, Sweden, involved a 6.7 MWp installation on a recultivated landfill with 11,928panels. In the Netherlands, the Bovenveld project involved a 6.3 MWp solar installation where the root system was crucial for non-invasive mounting on a sensitive geomembrane.

In a recent project in Rosental an der Kainach, Austria, TreeSystem was employed in a 4.5 MWp project on a recultivated landfill, where a complete mechanical and electrical installation of 8,128 PV modules, 39 inverters, and 64 kilometers of DC cables was carried out.

A Special System for Special Applications 

With its versatility, structural integrity, and non-invasive installation process, root systems are the preferred solution for a wide range of solar projects, including demanding applications such as landfill recultivations. The innovative design of the system, inspired by natural root structures, allows for the secure anchoring of solar panels with minimal environmental impact.