Transmission operators have little incentive to build costly infrastructure for unstable power sources.
Control over the grid allows them to impose high transmission fees, especially on renewable energy producers.
This is because renewable energy cannot operate independently without backup power sources.

2016-03-24
The following is a continuation of the previous section.
To begin with, why should a transmission company build towers across steep mountains and valleys and string transmission lines by helicopter for such unstable power plants?
As long as they control the transmission network, they can use freely imposed transmission fees to keep a firm grip on countless small power producers.
From the standpoint of a transmission operator, this would be absolutely undesirable.
There is little managerial benefit.
They would simply tell the new power producers to build the lines themselves, and then reach a compromise by imposing high transmission fees during negotiations with those who come pleading.
Renewable energy sources with particularly high selling prices would be subjected to mercilessly high transmission fees.
This is because they cannot stand on their own unless even backup power sources are provided for them.