BESS Development Project: 20MW Battery Energy Storage System on Screw Pile Foundations

OVERVIEW

A robust foundation solution with minimal disruption for a new BESS project

RADIX Screw Piling was approached to provide the screw pile foundations for six strings, each consisting of a 3.63MVA PCS Power Electronics inverter unit, a Power Electronics single MV skid, and a 3,700KVA transformer.

Each skid unit required foundations capable of supporting 280kN, and each PCS inverter required foundations to hold 90kN.

With the site beside the operating business, a solution causing minimal disruption was preferred.

SOLUTION

Battery Energy Storage System brought online on screw pile foundations

Given the combined weight of the skids and inverters, a point load test was conducted to fully understand the site’s ground conditions. As a result, 2m RADIX Extendable Screw Piles were selected, as sufficient depth was required below ground to ensure each string could be supported.

As the existing base consisted of a concrete pad, the first task was to diamond drill 200mm holes into this concrete to ensure the accurate installation of the screw pile foundations. A total of 84 screw piles were installed, with eight supporting each skid and six screws allocated to hold the lighter inverter units.

The additional length allowed each unit to be raised to the minimum requirement of 350mm above ground, allowing for the bending radius of the cables, which had to be attached underneath the units.

As the strings were supplied on custom subframes, the team fabricated timber templates for setting out the screws, ensuring they were correctly located. To complete the project, the screws were installed using a tracked excavator with the appropriate auger and drive attachments.

Using screw piles expedited the delivery of this battery energy storage system, but it also sat well with the customer’s business ethos of working towards a Net Zero UK.