Yeah, I'm guessing MidAmerican is behind the local TV ads I've been seeing that are purportedly from the "REAL Coalition" although this "coalition" will not and does not say who is bankrolling them.
Their anti-solar TV ads are very misleading and I've been harassing them on their FB site about it for a while now, with no response from them, of course. The reality is that all MidAmerican customers pay a monthly up front grid access fee, as you mention, and all customers should continue paying the same fee. If they have a problem with solar customers as things are I see two possible solutions for them:
1. Don't "buy-back" power from solar users when their panels are generating more power than is being used by the household. As I've done more research on the issue, I've found that this is their main hangup. Solar users generate more than they use during the day and sell that overage back, then use power from the grid at night. Just make it a one-way power stream. I don't know a ton about home solar setups but I would think those households could get something like a power wall to store the power they generate for using later, if they so choose.
2. Increase the standard monthly grid access fee for ALL utility subscribers, period. If their concern is truly with being able to maintain the viability and safety of the power grid and having the funds to do so, then just raise the rates for all customers. Don't try blaming it on solar users - that's disingenuous.