Do not go on typical sites like EnergySage- its a complete waste of time and they will resell your phone number to dozens of companies that will blow up your phone for literal months.

I have attempted to do this twice- the first time was at the end of February 2020, and everyone ghosted on me because of Covid. Regardless, dozens of companies called me after I put my info in on some sites like energysage but almost all of them ran away when it was not your stereotypical single family house. The last time was this past spring/summer. I didn't love the quotes because they couldn't guarantee anything specific due to supply chain issues- and panel quality can very tremendously, and a warranty doesn't mean anything if its from some fly by night company in China. I shelved it, as the IRA had just been passed, and we had some family health issues, waiting for a better day when you can just buy panels without issue. The IRA should hopefully bring costs down as well when it fully kicks in.

Anyway, Greenhouse Solar and Apex Solar were two companies that were actually willing to do the work (and that's all I could find). I found these companies by looking at a database online of actual installs that listed, the date, size, address of the install, and the company who did it that exists somewhere. I can't seem to find it at the moment, which is frustrating. I begged Brooklyn Solar to give it a go, but they politely declined. I also wanted a battery as well. These guys were balking, until I made it clear that I am not too worried about payback periods and such with a battery system. Of these two, Apex seemed like the much better option, an actual knowledgable person spoke to me, did not panic when we veered off his script- I had all the numbers already worked out in terms of payback or not. There are multiple issues with brownstones/townhouses- the biggest is the roof area and the fire code. You need to be at least three feet away from anything up on your roof- a skylight, AC equipment, the edges of your building, so firefighters can potentially get up there. This dramatically limits the amount of panels you can fit up there. My house has power lines in front of it, so there is even extra BS/permits terms of getting a crane to get the stuff up on the roof. There is also the issue that no one wants to puncture a flat roof, so you need to get a ballasted system, which means you need to get approval that the roof can handle the additional weight, etc.

Another option is to go with community solar. There are several projects out there, I went with solarlandscape.com. It seems like a scam- a guaranteed 15% off your bill and you get powered by solar? But its worked, and while they seemed to have figured out their issues, I was actually getting like 80% off my electric bill for awhile. I wasn't going to complain about it.

Finally, you can attempt to DIY a part of it- I seriously considered this. Companies like renvu solar: https://www.renvu.com/ Will design a system for you, and get all the permits taken care of, for a very reasonable price- $500 for their "full" package. You can then subcontract out the rest. I came up with a way to get a small jack/crane on my roof, so I could hoist all the stuff up there, that seemed to be a major sticking point for most of the little guys doing single family homes. They didn't want to deal with cranes.

Anyway, send me a DM if you want to discuss further. I really want to do this but it just has not worked out... yet.