An introduction to thermogeology. Ground source heating and cooling / Введение в термогеологию. Эндогенный источник нагрева и охлаждение

Many of you will be familiar with the term geothermal energy. It probably conjures mental images of volcanoes or of power stations replete with clouds of steam, deep boreholes, whistling turbines and hot saline water. This book is not primarily about such geothermal energy, which is typically high-temperature (or high enthalpy, in technospeak) energy and which is accessible only in specific geological locations. This book concerns the relatively new science of thermogeology. Thermogeology is the study of so-called ground source heat: the mundane form of heat that is stored in the ground at normal temperatures. Ground source heat is a much less glamorous topic than hightemperature geothermalenergy and its use in space heating is often invisible to those who are not ‘in the know’. It is hugely important, however, as it exists and is accessible everywhere. It genuinely offers an attractive and powerful means of delivering CO2-efficient space heating and cooling. Let me offer the following definition of thermogeology: the study of the occurrence, movement and exploitation of low-enthalpy heat in the relatively shallow geosphere. By ‘relatively shallow’, we are typically talking of depths of down to 200 m or so. By ‘low enthalpy’, we are usually considering temperatures of less than 30◦C.1 <...>