Introduction: This project is developing a Geographical Information System (GIS) to assist in the prioritising of future maintenance of rural ground earthing systems, by providing a graphical presentation of ground conditions and the probability of the resistance of legacy shallow trench earthing changing significantly under future project climate change scenarios.

The project will also produce seasonal variation correction factors for both deep drive and shallow trench installations to allow the existing and new GIS tools to respond to seasonal variations

Objectives: The Phase 1 Electrical Earthing project: An Information System to assist the installation of rural ground earthing systems was concerned with predicting the earthing requirements at sites within the network distribution areas of Western Power Distribution (Midlands) and UKPN. The project assumed that the installation of vertically inserted deep drive rods was the normal method of providing earthing systems and that a horizontal trenched system would only be considered when the ground conditions prevented this normal method.

The Phase 2 Electrical Earthing project: ‘Climate change and seasonal variation impacts on electrical earthing installations’ aims to investigate the temporal changes in earthing resistance. It is recognised that the earthing resistance of a system will change with time as the resistivity of the ground varies exponentially in response to changes in water content and temperature. In particular the value of legacy shallow trench earthing systems will be particularly affected. A number of climate change scenarios are available from climate modelling and these indicate that parts of the UK could experience dryer or wetter conditions and that the seasonal ranges of precipitation and temperature could be more extreme than today.

This project will provide qualitative and quantitative assessments of both seasonal changes and the impact of climate change on electrical earthing installations. The results of this study will provide a tool to identify those areas where earthing installations are most likely to go out of specification in future years.