There's a lot of noise about the Paris Agreement these days! Dozens of mayors across the US have pledged to adhere to the goals of the agreement anyway, and I figure a lot of them probably don't know some of the details of implementing a green energy solution.
Here's the three points I think a lot of people miss:
1) Green energy is getting cheaper all the time, but don't forget that you actually need to see if it's working. Unmetered systems are often installed wrong and are basically a waste of cash. Especially for large systems, make sure monitoring and emergency alerts are part of the spec!
2) A lot of people are upset that green energy doesn't produce on a perfect schedule. For now, there's plenty of low-hanging fruit: green systems can supplant normal power grids when they're working, and the grid can fill in when they aren't. Later on, when you have peak green energy above your power usage, you can start thinking about complicated things. That's not any time soon for most of you!
3) There's obviously no space for a ten-acre solar farm in the middle of New York City. Your green energy installations will have to work within the city footprint. That mostly means rooftop installations. Most rooftop installations are smaller, and therefore your incentives should be aimed towards small installs. Local cooperatives and programs already exist in every major city, look yours up and chat about their successes and failures.