SystemsΒΆ Documentation for system models and components. Subsystem Components Refrigerant Cycle Thermal Storage Tank Borehole Heat Exchanger (BHE) Solar Thermal Collector (STC) Photovoltaic and Energy Storage Systems (PV + ESS) Integrated Systems Air Source Heat Pump Boiler (ASHPB) Ground Source Heat Pump Boiler (GSHPB) Hybrid Heat Pump Systems Scenarios & Analysis Photovoltaic vs. Solar Thermal Collector