When Sacramento officials proposed putting solar panels on an old city landfill two years ago, they did so with the intention of providing clean energy to thousands of homes.

However, in a twist that surprised many at City Hall, the people who might be expected to celebrate such a green venture ended up being the plan's loudest critics.

Environmentalists and wildlife advocates argued that the field in Sutter's Landing Park – sitting atop a mound of buried trash that boasts majestic views of the downtown skyline – is a key feeding ground for the threatened Swainson's hawk.

The hawks, a big draw for visitors to the park, are often seen diving to the mound to feed on mice living in the tall grass. That grass – and those mice – would have been hidden by a field of solar panels.

Now, instead of an expanse of solar panels, the city is working on a scaled-back facility that will cover roughly 2.5 acres near a parking lot and dog park, and power a few hundred homes.

"Initially, I thought it was kind of absurd to oppose putting solar panels on top of a mound that was an old garbage dump," said City Councilman Steve Cohn. "But I was educated. In this case, (the environmental groups) had a point."

It's the kind of debate being waged across California. Cities, counties and utility companies continue to jump into a wave of green technology, seeking to cut back on energy costs and protect the environment. A state law signed by Gov. Jerry Brown last year requires that utilities generate one-third of their energy from renewable sources by 2020.

But as solar farms pop up on farmland and deserts throughout the state, officials often face stiff opposition from environmental groups trying to protect wildlife and delicate habitat.

In the desert of San Bernardino County, environmental advocacy groups are fighting plans for a 4,600-acre solar panel farm on a stretch of land they say provides pivotal habitat for desert tortoises, burrowing owls and bighorn sheep.

Advocates also are fighting a solar project in the Panoche Valley of San Benito County – roaming territory for the endangered San Joaquin kit fox.

At the same time, solar farms placed on unusable land, especially former farms no longer able to support crops, are lauded by those same groups.

"There's sort of this needle you have to thread of trying to find low-impact areas," said Kim Delfino, the California program director for Defenders of Wildlife. "We definitely want to see more renewable energy, but we have to realize that if an area has a high (wildlife) habitat value, that area loses value (when solar facilities are built)."

In many ways, solar projects are not unlike new subdivisions and malls. Proposals are often met with intense scrutiny from residents and ranchers. Elected bodies debate plans for months, and regulations are intense.

Still, the push-back aimed at the Sutter's Landing project – small compared with many projects – surprised some officials. The landfill cannot be developed with recreational facilities for another 15 years, until the ground settles; city officials saw the solar plan as a potential model for other urban solar projects across the city.

Once the opposition became clear, however, the city and the solar developer, Conergy, quickly regrouped.

"You have a landfill, but it's one of the most beloved landfills in all of the world," said David Vincent, a Conergy project development manager. "Even though you can't do anything on that mound, it still gets a lot of use. Everyone realized this really wasn't the right spot."

Originally designed to cover at least half of the former landfill and produce 20 megawatts of power, the new plan calls for a facility that will create 1.5 megawatts, about enough to power 400 homes. Panels will provide shade, and officials are hoping the facility acts as an educational tool for area schools.

Bolstered by a $1.6 million grant from the Sacramento Municipal Utility District, officials hope to break ground on the project next year. While terms of an agreement with Conergy have not been finalized, city officials plan to use revenue from lease payments made by the company to upgrade the 172-acre Sutter's Landing Park.

In scaling back the plan, city officials have eased the pressure from environmental groups. Jude Lamare, president of Friends of the Swainson's hawk, said her group is now "agnostic to this project."

"The developers and the local governments want to go full-speed ahead and not pay attention to the ways to protect the environment they're in," she said. "But this was an eye-opening experience that (solar projects) can be done and protect habitat. We're really pleased the city took a big step back."

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