Particularly at higher temperature, this would compete with resistive electric heat. That could be better than it sounds, since if you go directly from PV to resistive heat you can skip inverters and grid connection, just use a low cost DC connection to the resistive heater (a maximum power point tracker could be useful but that can be cheaper than an inverter). The heat is then very storable, and becomes more storable at higher temperature, as each unit mass of storage medium stores more energy.