Implementing the GEOPEAK Project in Greece towards the achievement of Europe 20-‐20-‐20 targets: Development and Evaluation of a Geothermal Heat Pump of High Efficiency - Vrachopoulos, M Gr; Koukou, MK; Tachos, N; Kalognomos, S; Adamidis, A; Lavrenti, F; Pappas, J; Xygogianni, P; Karytsas, C (2014)