In the communities in my neighborhood the talk is about having the various HOA's install solar and the solar energy companies put it on a lease.
The cost model they're looking at is net zero to the HOA and people who live in the homes since the net energy savings goes to the solar install company until the install + interest is repaid. It's an interesting model, and makes much more sense than having to pre-pay the entire install up front (which is cost-prohibitive for most people).