Within the heat pump sector, there are applications where photovoltaic/thermal (PVT) collectors can offer greater value with lower investment costs than the current alternatives. The first is ground source heat pumps (GSHP) with under dimensioned boreholes. The second is a solar source heat pump (SSHP) where the PVT collectors are a replacement for the traditional air heat exchanger in an air source heat pump (ASHP). Complete systems models for a multi-family house are simulated in TRNSYS to determine seasonal performance factors (SPF), which are then compared technically and economically to each respective alternative. A 156 m(2) PVT array is capable of improving the SPF of a degraded GSHP by 30%, the same gains as drilling additional boreholes but at a lower cost. The SSHP with a 235 m(2) PVT array can reach an SPF of 2.6, comparable to the performance of an ASHP, but has the cost of a GSHP. Already today, PVT can economically compete with borehole drilling for GSHP and the SSHP concept shows enough market potential to warrant investment and development towards broader adoption.