The image processing described is very cool, but I have questions about the application. Google started doing these solar potential estimates about 10 years ago, so let's imagine that they have been developing the capability since about 2010 or so. In that time the cost of PV has fallen by an order of magnitude. Hasn't that settled the question of where PV should be installed? I thought the answer is now "yes" everywhere.
Even assuming 100% solar rooftop coverage is the goal, given limited capacity of raw materials, labor, infrastructure would still necessitate prioritization of when to allocate those things to which places.
But the audience isn't an omnipotent controller of PV panel allocation, it's emergent market participants. Presumably, the market emerges more plentifully in those sunnier places. It's hard to imagine the place where this data is useful to local construction firms who were previously not well-informed (potentially by just walking around with their eyes open).
Maybe it's useful when trying to justify solar adoption. If you have control over some level of panel allocation, you could use something like this to explore where you'd want to put panels first -- answering the question of where are you going to make the best economic case for solar panels.
Then, once the top places are addressed, you can move onto the second tier of locations, then the third, etc...
This could be helpful if you're in gov't and have some control over a pilot neighborhood project. Or a developer that wants to include solar on some homes/businesses and wants to know where it makes the most sense.
You're right that this probably isn't too much better than qualitative reasoning about how sunny certain places are, but this is quantitative, so you can have a little more confidence in your qualitative assessment.
There are several allocation opportunities I could think of. You’re a local government considering some subsidies for rooftop solar initiatives. How much bang for your buck will you get? You’re a regional grid operator and have some estimates for rooftop solar adoption. How do you translate that into plans for future grid capacity needs? You’re a rooftop solar installation company. What neighborhoods do you send your mailers to?
Perhaps those three different groups should just coordinate together, rather than individually using this data, and arriving at three different and possibly interfering conclusions.
Aside from that grid operators buy power from producers. They don't plan future capacity more than 72 hours in advance. If you're a producer with expensive power you won't sell much. If you're a producer with cheap power you will sell a lot. It's already a functioning market. Solar is a very small part of it.
A lot of new homes are still constructed without solar. Either market participants are sleeping on easy money or the answer isn't a simple "yes, everywhere".
The cost of panels has fallen a lot, but the cost of mounting hardware and installation is still pretty high in the US.
