Construction World Septemer 2017

ALTERNATIVE POWER

Solar plants – MANAGING the LIGHTNING RISK

Engenamic CEO, Ian McKechnie.

Important aspects and elements of such a solution include, for example, direct strike protection, site-wide equipotentialisation, and the careful, considered and consistent definition and application of lightning protection zones (and of their boundary management) – the latter includes the appropriate and coherent application of surge protection as well as appropriate cabling practices (including shielding). Engenamic professional team members have been at the forefront of developing and internationally publishing a structured systems engineering and strategic approach to holistic lightning safety and protection solutions. Engenamic advocates, in principle, the use of such an approach philosophy, tailored to the application and applied through the use of appropriate professional expertise, as key to achieving effective and sustainable lightning safety and protection solutions. Engenamic’s professional services are offered and available internationally on a worldwide basis. In addition to engineering and project consulting, these services also include the Engenamic team’s particular expertise and experience in ‘troubleshooting and fixing’, including forensic engineering, and dispute resolution support. Engenamic professional team members are also available for appointment as mediators and adjudicators.  The nature and characteris- tics of such plants required a careful consideration of the risk assessment methodol- ogy, including the judicious use of risk areas or zones as appropriate.

Engenamic, with their team’s leading specialist professional engineering expertise in the field of lightning safety and lightning protection, observe that there are particular general characteristics of such sites and applications that contribute to their exposure and vulnerability to the deleterious effects of lightning. Engenamic CEO and principal advisor/ consultant Ian McKechnie noted that “in particular, they present a complex site and application environment, and this complexity impacts directly on the broad- based risks and engineering (and other) management challenges associated with lightning safety and lightning protection”. Engenamic noted that these are typically large and geographically extended sites, with factors such as the extensive interconnected electrical and electronic equipment and system elements adding to the complexity and challenges to be addressed and managed in a holistic and integrated manner. Often these sites are located in areas with difficult grounding conditions such as poor soil resistivities, which together with the extended and interconnected nature of these plants, adds to the challenges presented in respect Solar plants, particularly (but certainly not only) large facilities such as utility-scale PV plants, present particular challenges in respect of lightning protection.

of ground potential rises and differential voltages across the site and between elements, and consequent risks to the interconnected systems and equipment. Plant equipment is also relatively exposed to both direct strikes and to the induced effects of the electromagnetic fields associated with lightning strikes. Engenamic commented, for example, that these fields can potentially affect and damage buried services (such as cables) as well as above-ground equipment. The damage to buried services (such as insulation damage) can also potentially only become apparent at a later stage (‘latent damage’). Engenamic also stated that while plants of this nature might not be extensively manned, this can vary during different times (for example during construction and maintenance) and the risks associated with injury must still be carefully considered, in addition to the risk of economic loss. On the topic of risk, Engenamic noted that the nature and characteristics of such plants required a careful consideration of the risk assessment methodology, including the judicious use of risk areas or zones as appropriate. In particular a qualitative risk assessment should inform any quantitative assessment (with appropriate selection of parameters), as well as form part of a ‘broad-based’ risk assessment. McKechnie commented that the nature of such plants and the associated risks emphasises the need for an effective, holistic lightning protection solution that is coherent across all aspects.

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CONSTRUCTION WORLD SEPTEMBER 2017