As the company that manages the generation and transmission of electricity in the central and southern part of Illinois and several other states prepares for a Monday vote on the first portion of transmission investments in a shift to clean energy, some are wondering why it is taking so long.Midcontinent Independent System Operator board members are expected to approve nearly $10.5 billion in new transmission investments. The grid operator estimates that these investments will provide $37 billion to $69 billion in benefits to ratepayers over the expected life of the projects. State Sen. Christina Castro, D-Elgin, said MISO needs to get 34 solar and wind projects sitting in their queue up and running as soon as possible. “If Ameren customers ever find…