Guidelines and the design approach for vertical geothermal heat pump systems: current status and perspective

Geothermal heat pumps are becoming increasingly popular due to their energy efficiency, rising energy prices, and them being a renewable or sustainable form of energy. However, design considerations and the regulatory framework have not advanced at the same pace. This work points to the need for design methods that consider groundwater advection where it is applicable, and a stronger regulatory environment, to ensure the sustainability of the geothermal energy sector. Related standards have been developed in a few countries; comparing them demonstrates some heterogeneity in the approach to the problem, criteria, and thresholds. While variances in thresholds can be geographically driven, synthesizing the criteria is a powerful means to more comprehensive guidelines. In particular, the interaction of heat exchangers with each other and the groundwater is a major concern. This review intends to provide the understanding needed to implement sustainable geothermal systems by highlighting the necessity for advancement of the current approach in design and standards, and providing direction for establishing improved design and standards. Particularly, by putting Canada in the international context, it is oriented to the Canadian audience and offers state of the art knowledge to professionals and authorities for a sustainable growth in this field.