PVT based Solar Assisted Ground Source Heat Pump system: modelling approach and sensitivity analyses


A solar assisted ground source heat pump (SAGSHP) system is a promising technology which pairs two widely abundant renewable energy sources, solar and shallow geothermal. In space heating dominated regions, the addition of solar collectors to conventional ground source systems improves their feasibility. There are many aspects which influence the system’s efficiency; but experimentation to optimize these would requires high capital investment and take a very long time. Therefore, mathematical modeling and computer-based simulations are preferable methods to conduct sensitivity and feasibility analyses.

In this work, a PVT based solar assisted ground source heat pump system was modeled using TRNSYS program, and sensitivity analyses were conducted. For the PVT collectors, an experimentally verified transient model was utilized, while experimental data were used to validate a novel very shallow borefield. For the heat pump model, manufacturer’s performance data along with a new novel method were combined, and a new component was created in the simulation platform. A single family dwelling with domestic hot water demand was assumed for the heating load, and weather data from Birmingham, West Midlands, UK was used. The simulation results were evaluated by utilizing the annual specific productivity metric rather than the systems seasonal performance factor, which is the current choice for SAGSHP systems. The proposed evaluation approach was found be capable of clarifying, in detail, the effect of the parametric variation on the system’s energy performance.

The sensitivity analyses are focused on six parameters on the energy conversion side, with the heat pump’s evaporator as the physical boundary. It was found that the storage capacity and the plate heat exchanger’s effectiveness, contribute the most to the system’s and PVTs’ heat productivity. Whilst heat productivity depended more on the parameters’ variation, the power generation was influenced mainly by the collectors’ tilt. The results of this study are significant for design and operation of these systems.


The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.


Solar, Ground source, thermal storage, PVT, Ground, SAGSHP


Sakellariou, E.I., Wright, A.J., Axaopoulos, P. and Oyinlola, M.A. (2019) PVT based solar assisted ground source heat pump system: Modelling approach and sensitivity analyses, Solar Energy, 193, pp. 37-50


Research Institute

Institute of Energy and Sustainable Development (IESD)