Folks, you need to think hard about what you are getting here. Yes, you will save money, but the savings will diminish as the years progress on your PPA. The first year, you will save about 30%. The PPA says they will raise your rates up to 2.9% a year. Take this, and the fact you have to sign a 20 year commitment, and the savings can evaporate.
SolarCity has much more to gain from using your roof than the savings you will have. Think about what other options will be available in 10 years. But if you go with SolarCity, you have to wait until 2035 to make a change unless you buy out the system.
READ the PPA very carefully before you sign anything. They will push you into singing very quickly so you don't have time to weigh options.
Think about what it will take to sell your home with their hardware on it. My consultant admitted that realtors need to learn how to sell homes with leased/PPA solar units on them. It's a whole new layer of negotiating your home sale.
Read what they do and don't cover. They don't cover "ball damage" to their hardware. How do they determine a ball strike if the owner does not admit it?
Read the part where cosmetic damage to your home is covered at their discretion.
Overall, I am not saying that SolarCity is a bad idea. I am saying that they will make a lot more off you than you will save on utilities with their PPA agreement.
Also, take note that you pay for ALL power your system generates. Even if YOU don't use that power.
Elon Musk (CEO) is no moron. The guys is a savvy businessman that is out to make profit. He wants as many solar roof gardens that he can get, but you only get some of the crops.