Case studies on soil heating by cables liners

This work examines various factors related to the heat balance of cable liners to demonstrate the complexity of the soil water and heat balance, and to show how useful it is taking changes in the heat balance into account when planning cable routes. The aim is to achieve optimal technological solutions by keeping effects on the surroundings as small as possible. The following aspects come up: technological issues around cable routes, soil physical basics and ecological aspects around cable routes. Heat dissipation from the cable into the surrounding soil depends on ambient conditions such as the site’s climate, soil properties and usage, and groundwater level. However, the key factor is the thermal conductivity of the surrounding soil. Soil heating also plays an important role in the ecological balance: In the amount of evapotranspiration left for the cultivated plants, and in the distribution and living conditions for the natural vegetation and soil organisms. This means that cable routes need to be assessed and improved not only with regard to the technology used, but also with respect to environmental site conditions.