To switch your energy provider you need your current electricity bill. All the information you need to change to renewable energy should be on it.
There are different options, but most let you keep your bill just as you have it now. You pay it in exactly the same way, nothing changes—except that your electricity will now be from clean sources!
Use the links in the left sidebar box to choose a clean energy provider!
Some famous residents of the city purchase some or all of their energy from renewable sources including Brooklyn Brewery (all), NYU (some, largest education purchase in US), EPA (some), Barcade (all, Williamsburg), and more. Know of any? Contact the webmaster.
A resource on electricity suppliers:
http://www.nypirg.org/energy/green_electricity/green.html
New York wind info:
New York wind