What are some standard process or contracts needed before the partnership to make sure both parties are protected?

Honor your contracts.

I assumed once I signed the contract, I owned the property, just land at that point, and have a contract to build the quad.As for if they run out of cash at 80%, I could close the gap if absolutely needed but obviously that isn't the goal.The builder owns the entire development, minus the handful that have/being built, so they have a vested interest in this working, they want to do it a couple of hundred times at least.

this is an old old program I had clients of mine doing this in Detroit back in the GFC they would buy a house 1 to 2k sell it on contract for 20 to 30k..

There are some reasons for this and why it is happening, the solar payment/bill increases incrementally each year until it ends, the company of the solar panels does not have great support, and the last thing, it is not a massive savings in eyes of the buyer with these burdens that they have to go through with an intense contract to sign too.   

We see fundraising wrapping up within the next 2-3 weeks.We're going to begin to put together pre-sale marketing collateral and contracts towards the end of this week.

Evolve seems like they charge less but a homeowners have to contract with a local cleaning crew and maintenance.

I have no clue what contracts you need.

If they don't, they likely contracted it out and added a 20% mark-up on the service. 

However, my number 1 went under contract before I could place a bid.