I am going to ask what happens if I sell my house but I will also ask about them essentially having a lien on my house.
Not trying to dampen enthusiasm (solar is definitely a large part of the future) but, uh yeah, questions like this I'd run past the appropriate division within my state's attorney general's office (or your jurisdiction's equivalent).
At the very least, I'd find an attorney willing, qualified and experienced in reviewing such contracts BEFORE any such agreement is even drawn up. Doing that "legwork" (yellow pages) in advance has saved me untold $tre$$.
The other partie's eyes and / or reaction say it all and tell me whether I'm entering into a true Win/Win contract or whether I've just dodged a huge bullet -- when they see damning (to me) language lines or entire sentences crossed out with spaces for them to initial acknowledgement.
Heck, one attorney even found fine print buried in one contract that legally made me PER$ONALLY RE$ON$IBLE for making payments on an installation, even if I sold the property! Most recently, it was identical language in an agreement my siblings and I were handed when trying to find assisted living for an elderly relative but, that's another thread . . .
Best o' Success (but, Caveat Emptor when anyone YOU ARE PAYING for a product requires YOU to sign a contract)!
WE KNOW the technology and concepts are sound . . . it's just SOME of the sales and marketing people on the lead edge of the wave of the future. I envy anyone able to build their own system, awesome!