Geothermal energy in loess

ASAL BIDARMAGHZ; NIKOLAS MAKASIS; GUILLERMO A. NARSILIO; FRANCO M. FRANCISCA; MAGALÍ E. CARRO PÉREZ

Environmental Geotechnics

ICE Publishing

Año: 2016

Ground-source heat pump (GSHP) systems efficiently heat and cool buildings by using sustainable geothermalenergy accessed by way of ground heat exchangers (GHEs). Loess covers vast parts of the world, about 10% of thelandmass; therefore, the use of piles or ?micropiles? is extensive in these areas, particularly where the thickness ofloessic soils is significant. These deep foundations have the potential to be used as ?energy piles? in GSHP systems,with a minimal additional cost. This paper presents a case study of a representative real building in Córdoba,Argentina, where foundations are also used as GHEs. The thermal properties of local soils were experimentallymeasured and used in recently developed detailed state-of-the-art finite-element models. Results from the realisticsimulations show that the partial substitution of electrical heating and cooling systems with geothermal systemscould significantly reduce energy consumption and the size of associated infrastructure, despite the relativelylow thermal conductivity of local loess. Moreover, the effects of surface air temperature fluctuations, which areroutinely ignored in GHE design, are accounted for in these simulations. This case study shows the potential of GSHPtechnology in loessic environments and gives incentives to engineers to start considering the technology in theirdesigns and practices.