After Kraft babbled on the fact that he was going to exploit the customers, Jin had no choice but to allow him to do whatever he wants mainly because the boss was not there to facilitate it. Besides, deep down, he knows that this would definitely be a money saving trick that he could employ in order to save on the electricity bills.
Perhaps, if they went large scale and if it was popular enough, he could be able to power up the Tree Mall with it and the cost savings could be past down to the vendors as well. Of course, some price expectations were needed to ensure that his tenants were also not ripping their customers off and expecting a revision of their prices or at the very least, keep the prices stable.
