Possibilities of underground engineering for the use of shallow geothermal energy

Abstract

Possible ways of using shallow geothermal energy, and capabilities of underground engineering in this process, are described in the paper. In addition to their basic role in ensuring bearing capacity or stability of soil and rock, reducing settlement of structures, etc., underground structures in direct contact with the soil, rock or groundwater can also be utilized as a part of geothermal systems where they can have an efficient role in the energy transfer process. In this case, they are referred to as "underground energy structures". The implementation of elements of underground structures as parts of geothermal systems is currently in its beginnings in Croatia.