Where some people see poop, others see brown gold.

Sanford, Fla., aims to be the first town in America to covert sewage sludge into energy, and has built a new "gasifier" plant to do so.

It's a completely closed-loop system made by a Houston company called MaxWest Environmental Systems. Nothing escapes.

There's no smokestack, and the heat and smoke that would normally be emitted is forced back into the system and used to keep drying more sludge.

Without this new process, the plant had to use expensive natural gas to dry its sewage sludge. The process instead converts treated sludge into renewable energy, essentially using the product to create more product.

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It sounds weird, but experts say there's a whole lot of "firepower" — a whole lot of energy — inside the sludge, which had previously been going to waste.

MaxWest built and maintains the plant — the town, known as the "Horse Capital of the World," didn't spend a dime.

The company says the town will save nearly 9 million dollars over the next 20 years by not having to buy natural gas, and the plant can process up to 100,000 tons of sludge a year.

MaxWest says other cities will be able to send their sludge to Sanford, meaning more "free" power for the city.

Other cities are still using old-fashioned and costly ways to dry their sludge, and then have to pay to haul it away. Lots of it gets used as fertilizer, but critics say that stuff gets in the ground water and isn't healthy..

With this new "gasifier" system, there's nothing left over and nothing to haul away, and with 35,000 horses within the city limits, there's always a big supply of raw fuel.