This is a diagram of how a dog poop-to-power project would work:
In 2010, he installed a demonstration methane digester at a dog park in Cambridge, Massachusetts, the Park Spark Project.
A project like this would almost certainly work at Harry Griffen Park. Not only do we have plenty of poop, we have a plenty of people who would put their poop in the digester. Since the park isn't open at night, we'd have to come up with another use for the power produced by the methane.
How much do you suppose such a project costs? I didn't find anything about that on their website.