Earthing Design Challenges and Opportunities for Utility Scale Solar PV

With exponential growth of utility scale solar development throughout Australia, the need for effective and optimised earthing design is highly present. Renewable energy projects are highly cost sensitive with a focus on shrinking upfront procurement cost. As a result, clever earthing design for these projects involves more than just meeting the requirements of Australian standards, as every additional bolt or small conductor length can be multiplied by many thousands due to the large number of trackers required throughout the array, resulting in huge cost increase if designs are even slightly over specified or poorly considered. Across each of these solar projects are multiple A.C. and D.C. voltage levels resulting in a large number of fault scenarios to consider, each with different earthing requirements. Along with this there is usually a number of stakeholders including a TNSP, DNSP, EPC, asset owner and sub-contractors. This paper discusses the challenges to an earthing designer of a utility scale solar farm in achieving a robust design that complies to relevant standards, whilst being acceptable to all stakeholders. It also explores the opportunity available to project developers and EPC teams to achieve the best outcomes including highest whole-of-life value.