Under both bills, the amount of biofuel mixed in with heating oil would increase over time. In addition, Gennaro's bill would place a cap on the amount of sulfur allowed in the oil.

"It's the most significant bioheat bill in the country," Gennaro told the New York Sun. "There are a lot of benefits to it. We have a concrete blueprint as to how we'll be the best bioheat city in the nation."

Both bills stand to make a significant impact on the Big Apple's greenhouse gas emissions, since 79 percent of them come from buildings. The proposals come on the heels of Gov. Eliot Spitzer's state budget proposal, which calls for tax credits to homeowners who make the switch to bioheat.