“…found that while the capital expenditures were higher than current solutions, if there was a cooling requirement as well as a heating load, the hybrid RTES could reduce energy costs by up to 70% (Gritzer et al 2018). Similarly, when PVT was coupled with heat pumps as a hybrid RTES, the thermally driven heat pump (which also had grid backup when the PV was not generating electricity), was not economically viable under conditions at that time, but could be valuable over a 20-year period (Sanz Martinez, Fuente Dacal, and Martín Miranda 2018).…”