A simple solution is, never enter into a business where direct or indirect conflict of interest exists.
At this time, even with owned miner, paying lower electricity charge or even free solar electricity,
it's difficult to profit from a mining device in the long run.
So when adding the conflict of interest in this formula and the total control is on the hands of cloud mining company,
just ask yourselves, who will win the race. You got your answer now.
Solar electricity is not free to set. It is only free if you get a free solar system.
It is in the best interest of cloud mining companies that everything runs out smoothly but some can be blinded by getting a short term profit.