> I don't understand the purpose of consumers owning individual solar panels in a large array. How is that better than a single entity owning the whole array, and what function does the consumer provide?

I don't now if it's better, but it is different.

The benefit to the utility in this case is much lower capex - it's basically like the restaurant franchise model, but for power.

But like you imply, there's a tradeoff that can be made between capex and opex - in this case, the utility could own everything and consumers could pay for electricity on an ongoing basis. IMO, this model is superior due to reduced principal-agent problems.