Techno-economic approach for optimum solar assisted ground source heat pump integration in buildings

Abstract

Two-step approach for optimum solar assisted ground source heat pump integration in buildings is proposed. At the first step energy targeting based on dynamic pinch analysis allows to target the energy and optimum equipment size according to buildings’ dynamic demands, and as a result, several energy efficient daily design candidates are extracted. At the second step of the proposed approach, a final design working for the whole year is selected among all the candidates by computing the total annual cost (TAC). A special algorithm is proposed to compute the yearly average energy and capital cost penalty for complementary hot/cold utilities in order to adapt the daily designs to the overall year design. As an objective function, TAC is defined for a 20-year lifetime design. Moreover, the TAC of several daily optimum designs (DOD) based on different scenarios are investigated for a multifamily test building. In the context of Canadian market, it is illustrated that the choice of the overall year integration design depends mainly on the electricity cost. For example, with Quebec electricity cost (i.e., 0.073 CAD/kWh), the DOD of September is optimal for the whole year, where there is no need for vertical ground heat exchangers. However, if Canadian average electricity cost (i.e., 0.147 CAD/kWh) is considered, the DOD of March is optimal for the whole year, with a vertical ground heat exchanger depth of 200 m. The DOD of September and March can reduce building’s annual electricity consumption by 55.9% and 79.2%, respectively.