This actually makes sense, it would be reasonable if they laid out that information when they send out proposals for using it, especially with more transparency.

Something like "Hey, we would like you to use this advancement in technology but currently the adoption rates are low, and due to that we are financially limited in our ability to update our infrastructure to support this new technology, so the rates are going to be slightly higher to offset that cost which will enable us to update the infrastructure at an accelerated rate so that we can provide electricity to you at a lower cost. Here is our current financial standing and this is what is required for us to be able to completely support the grid in your area. Once this project is complete then your rates will go down to x amount"

At the same time though, they could slightly increase the cost of fossil fuel usage to match the increase they are charging for renewables in order offset the cost of upgrading the infrastructure at an accelerated pace.

I'm quite pessimistic when it comes to things like this, because I believe even if the infrastructure was there the rates would still be as high as using fossil fuels simply due to capitalism. Charging less for electricity (or anything for that matter) due to cheaper production, maintenance, or other factors impacts the money that the rich are getting and it has been shown time and time again that the rich will not accept that.