Payoff for geothermal heat pumps using shallow ground heat exchangers

A discounted cash flow analysis (DCFA) and a cost benefit analysis (CBA) have been implemented in order to nvestigate the economic aspects of ground coupled heat pump (GCHP) for space heating and cooling, in comparison to traditional condensing boiler (CB). The DCFA allows the analysis of investment costs, operating costs and savings of the two different systems in order to understand if the GCHP’s pay back periods (PBPs) period is more interesting than CB in coming years. The first financial model (DCFA) takes account for economic factors as prices, costs and growth, while the economic approach (CBA) include the carbon price into the calculation, considering the social costs of carbon dioxide emissions. The whole analysis is implemented adopting a parametric approach, in which all the economic terms are linked to energy labels, degree-days and energy mix ratios (EMRs), the latter obtained as ratio between the cost of electricity and natural gas paid by the householder. Relating to different EMRs, the PBPs are presented in matrixes in which energy labels and degree-days are the row/column variables, to confront the benefits of choosing between GSHP versus CB. The PBPs are also calculated with the introduction of the carbon price, so that some considerations about the environmental aspects are presented. The results show that all higher energy labels have a good profitability ratio between costs and payback periods and demonstrate that GCHP system does pay off.