This is a story that Billy, Dolly and the rest of the elephants at the Denver Zoo will probably never forget: how they almost, but not quite, became not just animals on exhibit, but also sources of renewable energy.

A decade or so ago, zoo leaders had an innovative idea. As part of their quest to become “the greenest zoo in the country” and a zero-waste facility by 2025, they would develop a technique to transform elephant dung and other waste at the zoo such as paper plates and dirty diapers into fuel pellets that would generate electricity through a process called gasification.

The power would help light and heat the 10-acre elephant exhibit and warm pools in which the animals wade and swim in the winter. The zoo estimated it would reduce what it sends to landfills by 90%.

The state and the city said yes. The Environmental Protection Agency was interested, as was the National Renewable Energy Lab. Permits were obtained. All was a go. The gasification plant would be built on the zoo grounds in the heart of Denver’s City Park.


The zoo showed off the potential of its pooh by powering a blender to make margaritas and, later, a motorized rickshaw that went on a promotional tour to zoos across the West. There was even a nice irony: This green electricity would be powering an elephant exhibit sponsored by a major consumer of fossil fuels, Toyota.

“Everyone was on board,” said Tiffany Barnhart, a spokeswoman for the zoo. “Everyone loved it.”

Nearly everyone.

As the years passed and plans proceeded, a small but persistent group of neighborhood activists began raising questions and applying pressure to the City Council. Would the plant disrupt peaceful City Park? Would it really meet air quality regulations? The zoo said of course it would — it would have to. The city’s largest newspaper stood up for the project this month.


“The zoo is trying to reduce its waste footprint through an innovative way to capture energy,” the Denver Post editorial board wrote Sept. 12. “It is a smart plan, one that has gone through extensive review and approval. Continued gripes from some opponents are misguided and, frankly, way too late.”

That prompted still more neighborhood reaction at a broader level. Larry Ambrose, president of Denver’s Inter-Neighborhood Cooperation, wrote back Monday, saying that the project needed more study and had been “unilaterally” approved by a parks manager appointed by the city’s mayor, Michael Hancock. He noted that his group had been frustrated by a decision several years earlier to take certain park zoning decisions away from the City Council, ostensibly reducing the ability of residents to influence policy.

Barnhart said opponents often mischaracterized the project as an incineration plant, which she said was intended to evoke danger and pollution, when in fact it would have operated through a safe and relatively clean gasification process.

So there were politics, but there were also questions of money, priorities and practicalities. The zoo had spent nearly $4 million during construction. Yet, while the plant was nearing completion, the zoo was still refining the development of the fuel pellets it planned to make from its diverse stream of waste.


“What we were still working on was pellet consistency,” Barnhart said. “How do you create a consistent pellet out of an inconsistent waste stream?”

Another factor: The zoo hired a new president and chief executive, Shannon Block. She started in March and began pursuing a substantial new master plan for the zoo.

Using elephant waste to make energy, it turns out, will not be in it.

On Friday morning, Block and other zoo leaders called the whole thing off. Sort of. Block said the zoo would no longer pursue the project, but hoped another entity, to be determined, would perhaps take the expensive equipment somewhere else and complete the plan.


“This project has elevated the scientific dialogue,” Block said Friday. “We want this technology to succeed. Although this is a difficult decision, it is the one that makes the most sense to ensure the project continues to completion off-site, and to ensure that the zoo achieves our highest priorities moving forward, including implementation of our new master plan.”

Whether the elephant poop is ever made into energy, it and the waste of other herbivores at the zoo will still have a noble second purpose: compost, or in Barnhart’s words, “garden amenities.”

william.yardley@latimes.com