Even as demolition proceeds on most of Villa Alegre, parts of the plan for what will replace the old public housing project on two parcels along West Alameda Street near downtown Santa Fe are still in flux.

According to Santa Fe Civic Housing Authority Executive Director Ed Romero:

• The authority is considering rehabilitating 10 of the old units at the east end of the project, adjacent to Alpine Builders Supply, rather than demolishing them.

• Photovoltaic systems planned for the project would provide electricity for senior housing and multifamily units on the larger, westernmost parcel, closer to St. Francis Drive, but not what has been dubbed "work-force" housing on the easternmost parcel.

• Ground-source heat pumps proposed as an energy-efficient method for heating and cooling would require drilling more than 100 holes as deep as 150 feet.

After hearing an update on the project Wednesday, the Santa Fe City Council tabled until next month the housing authority's request to divide its single lease on the 9.5 acres of city land into three leases.

Romero said separate leases would allow more options in financing the redevelopment project, proposed as a "LEED platinum" project — the most stringent green-building designation of the Leadership in Energy and Environmental Design organization.

Although lenders are lining up for the senior and multifamily units, which are eligible for federal tax credits, he said the so-called "work-force" units remain without backers or tax credits, and would best be developed independently.

Romero urged the council not to put further limitations on the work-force units that could jeopardize financing.

But Councilor Patti Bushee said she was disturbed to learn that even as most of the old public housing units from the 1960s are being knocked down, 10 units remain standing and might be rehabilitated.

"You have pretty much stated ... that these (units) were in horrific shape," she said.

The original plan envisioned 4,000 square feet of light commercial space on the site, on the east side of Camino del Campo, but as the project progressed, Romero said, rehabilitating the 10 efficiency apartments there looked more cost-effective. Only four new residential units would fit on the site, he said, so fixing up the 10 existing units would mean more than the originally planned 110 dwelling units could be created in the complex.

Romero said he had heard no complaints from neighbors about the idea of not razing those existing apartments. Roofs, flooring and windows would be replaced so that the old units would match newly built ones, he said.

Councilors also questioned plans to power only two-thirds of the development with photovoltaic panels.

All-electric units are planned. Concerns that this would be more expensive for the residents than natural gas and would cause more greenhouse-gas emissions — because coal-fired generating plants provide most of the electricity here — caused Romero to turn to solar energy to save on electricity from the grid.

Romero said he has secured federal grants for $1.5 million worth of photovoltaic panels capable of generating 200 to 250 kilovolts — enough to cover heating, cooling and hot-water needs of 110 units. He said the solar-generated electricity would be shared among residents of the multifamily and senior units. But under questioning, he admitted the solar savings won't apply to the work-force units.

Some councilors seemed particularly troubled by the news that ground-source heat pumps planned for the new units would require drilling 111 holes up to 150 feet deep — what Romero said would be the largest application of such a system in New Mexico.

Nick Schiavo, the city's energy specialist, said he only recently heard about this plan and that although he agrees that heat pumps provide efficient heating and cooling, he believes a permit to drill that many wells on the site might be challenged before the State Engineer's Office because of concerns about drilling into the water table.

Romero, however, said there would be no contamination of the water table. He said the drilling would not create wells, but rather closed-loop systems through which a solution is pumped into the ground and drawn back up where heat pumps extract the energy.

Councilor Chris Calvert remained unconvinced. "This is pretty problematic," he said. "It's also real close to the river, so I'm sure the water table will come into play."

Contact Tom Sharpe at 986-3080 or tsharpe@sfnewmexican.com.