New York City is an island built on garbage. Dutch settlers constructed much of the southern tip of Manhattan by extending the shoreline with landfill. But today, waste management is a major issue–and we’re running out of room. New Yorkers generate at least 10,000 tons of solid waste per day, much of which is hauled out of the city by greenhouse gas puffing biodiesel trucks. It’s not exactly cost effective either, at $300 million spent on this export process annually. That’s why, as part of the city’s effort to double the amount of waste diverted from landfill, Mayor Bloomberg called for proposals earlier in the week for a “state of the art conversion technology facility” that didn’t feature mass trash incineration. So, what does “conversion technology” even mean? Here’s a list of 10 ways, some real and some imaginary, one might convert waste to energy, from oil rendered from denatured turkey guts to Back to the Future’s Mr. Fusion.