Update: I just received a note from Clean Power Finance (CPF) that corrects and clarifies some important points I was not previously aware of. Here’s the full note from CPF:
We are working jointly with ProjectPermit.org, as they are pulling a subset of our data to do their rankings. The same data that is found in their database thus can be found in ours. The main difference is that their goal is active advocacy and will therefore be pushing for reforms. SolarPermit.org is an unbiased repository of information with the overriding goal of increasing transparency for all stakeholders—with a particular emphasis on the installer, as they are the ones who bear the brunt of permitting costs. That’s why we include additional information that ProjectPermit.org doesn’t have (e.g. which NEC code they use or load requirements).
Additionally, the database is also designed to engage the AHJs themselves, as we are looking to reduce the misunderstanding and miscommunication that frequently occurs between the installer and the AHJs, which in turn drives up cost for both sides. SolarPermit.org will thus not make judgments on AHJs, lest we scare away an important set of contributors to the database.
Finally, it should be noted that the two projects are complementary, not competing. The redesign of the database was timed specifically with Vote Solar’s launch. One of the reasons we did not make a big announcement is because we didn’t want to steal Vote Solar’s thunder and give the impression that the two projects were competing. Moreover, the public should think of us as the official, objective scorekeeper and the Vote Solar is the color commentator interpreting the stats that we are collecting.
It’s no secret — permitting requirements for solar power are one of the key things that need to be improved in order to get more solar power installed across the US. Recently, a new site — Project Permit — was launched to help that along. Now, Clean Power Finance has announced that its solar permitting site — SolarPermit.org — has been revamped to also help the process along. 
“SolarPermit.org hosts the National Solar Permitting Database, a free, online database of solar permitting requirements for cities and counties across the country,” Clean Power Finance wrote in an email to me. “Developed by Clean Power Finance and supported by a Department of Energy grant, SolarPermit.org organizes and simplifies the solar permitting process by compiling permitting information in a single location. Using a community-based platform, users of the database keep the information up-to-date and relevant.”
The database includes information for about 80% of the “most popular” jurisdictions. What does “most popular” mean? It means jurisdictions that have 200+ residential solar installations per year. Information you can find in the database includes: “contact information, turnaround times, fees, specifications for system designs, inspection processes and common errors.”
As a user, you can also input information and vote on information provided to help validate it.
Notably, SolarPermit.org does have a lot in common with Project Permit. However, Project Permit gives an overall ranking (crowdsourced) of how good or bad the solar permitting process is in particular places. SolarPermit.org seems to have a lot more information available for installers, but Project Permit offers a great snapshot view of which jurisdictions seem promising for expansion (at least, as far as permitting is concerned) and which need to improve their permitting requirements before you’d want to try to make it there. Additionally, Project Permit is a great site for shaming solar-unfriendly jurisdictions and motivating local installers, residents, or policymakers to work on changing the policies there.
