There are basically two industries: grid, and residential. A massive plant like a car factory has a huge roof, they might be able to get the grid people to show up with their contracts.

Multi-family homes would probably be punted to the residential sector.

Part of the residential issue may be that the utilities are so balkanized across the US. If we had some national residential companies that could do aggressive negotiation and train and cost-cap installation...

Tesla solar was doing some interesting stuff with google maps for initial estimates, and the like. General Electric once upon a time before Jack Welch turned it into a hollowed-out zombie would have been another.

The power companies can't be trusted, fundamentally you'd be paying them to undermine their raison-de-etre: centralized power generation and central importance of the grid. No CEO looks at "hey, how about you distribute and lose control and ownership of your core product" and jumps at that thought. You need a well-funded external player.

Honestly, some company like Uber who DGAF about local regulations and has a playbook for providing a service with overwhelming value and using that to completely undermine the balkanized local regulations and entrenched power structures.

Uber sucks for many reasons, but the taxi services SUCKED and were local monopolies, and Uber pushed them to modernize to some degree.