Geoelectric Modelling of Near-Surface Resistivity Distribution for the Design of Windfarm Grounding Grids
P.P. De Lugao, B. Kriegshäuser and P.E. Freire
Event name: 1st Conference on Geophysics for Infrastructure Planning, Monitoring and BIM
Session: Geotechnical Infrastructure Condition Using Geophysics II
Publication date: 11 September 2019
Info: Extended abstract, PDF ( 854.89Kb )
Price: € 20
The design of grounding system of windfarms and large solar plants, which can be in the order of a few kilometres size, requires deeper geoelectric models than the usual models developed for the design of a typical electrical substation. The average apparent resistivity curves of windfarms located at the Northeast of Brazil, in the states of Bahia and Rio Grande do Norte, reveal that, in general, ground resistivity is high at these sites, resulting in high grounding resistances for the windfarm towers. In this study we propose the use of 1D geoelectric models built from the combination of two types of geophysical soundings - the traditional Wenner.array method, which provides resistivity distribution of the shallow ground, combined with the AMT – Audio Magnetotelluric Method, which can investigate the resistivity distribution of the upper few kilometers.