Conference article

A DCF model (discounted cash flow model) is implemented in order to investigate the economic aspects of GSHP (ground source heat pump) for heating and cooling; in comparison to traditional CB (condensing boiler). The DCF model allows the analysis of investment costs; operating costs and revenues of the two different systems in order to understand if the GSHP outperform its conventional counterpart in coming years; explicitly taking account for factors as price/cost growth. The whole analysis is performed adopting a parametric approach; in which all the previous terms are linked to energy labels; degree-days and EMRs (Energy Mix Ratios); the latter obtained as ratio between the full unit cost of electricity and natural gas paid by the householder. Relating to different EMRs; the DPBPs (Discounted Pay Back Periods) are presented in decision support matrixes in which energy labels and degree-days are the row/column variables; to confront the benefits of choosing between GSHP versus CB. Some considerations are also presented in order to express the environmental aspects. The results show that all higher energy labels have a good profitability ratio between costs and payback periods and demonstrate that GSHP system does pay off. Lower labels become interesting when the EMR drops to 0;25 and the gas price goes up 0;70 €/Nm³.

Ground source heat pump; discounted cash flow models; energy mix ratio; decision support matrixes