Comment by pfdietz

> Heat pump have problems to reach high enough temperatures for most industrial heat applications.

They do if you start from ambient temperature, but they can be more effective if they are pumping heat out of the waste heat stream of a process. This requires different working fluids than lower temperature systems, though.

Most industrial heat energy is not consumed at very high temperature. IIRC, 2/3rds is at less than 300 C.

Electric resistance heating might also allow PV to dispense with auxiliary equipment, like inverters, so even if inefficient that might not matter as much. Heat also allows easy long duration storage at scale, even at rather high temperature, so resistive heating can be used with intermittently available cheap surplus power.