Knowing the soil thermal conductivity can help with the power load on underground power cables.
Recently, Victoria had large bush fires that caused loss of life and millions of dollars of damage to homes and the states infrastructure. It has been reported that some of the fires where caused by power lines sparking in the high winds. With underground power the threat of such devastation is eliminated. But with every panacea there is always a down side. As you are no doubt aware power cables give off heat. The more power through the lines the greater the heat. If in underground power lines this is not properly accounted for this heat can build and at best slow the through put of power in the cable to at worst melt it. As all soil reacts differently with respect to heat absorption soil thermal conductivity or soil thermal resistivity testing is essential. The expense incurred by testing is always a small component of the over all construction cost compared to the devastation caused of catastrophic failure or the over-capitalisation of increasing the size cable.