TROY, N.Y. — After many years of starts and stops, the Energy Center Building for the geothermal project in downtown Troy gave its site plan to the Planning Board earlier this week. “This could be a huge home run for the City of Troy,” Mayor Carmella Mantello said in an interview with The Record on Wednesday morning. “We talk about cleaner, greener all the time, but this unique partnership with National Grid would be the first public-private par…