for the miner it is necessary the whole field of solar batteries. energy consumption is too high and large storage batteries are needed
An extension of that is that mining requires a constant supply of energy, and solar alone
can't provide that. Either the mining equipment sits idle at night or the system requires
batteries for storage. Either reduces the potential for profit significantly.
Solar power works best when the energy can be stored cheaply in a different form,
or when it's consuption can be scheduled to coincide with generation.