Abengoa announced last week that it had bought out BrightSource’s interest in Palen Concentrated Solar Power (CSP), and that it would develop the project on its own.

Abengoa Solar plans to build the Palen Concentrated Solar Power (CSP) project with just one solar tower, but it could be months before more details about the developer’s proposal emerge.

It’s been a wild year for Palen, which was set to be approved by state regulators before its developers — Abengoa and BrightSource Energy — suddenly dropped the project in September. But Abengoa announced last week that it had bought out BrightSource’s interest in Palen Concentrated Solar Power (CSP), and that it would develop the project on its own.

Abengoa has been tight-lipped about about its new proposal, but the developer told The Desert Sun on Tuesday that it would propose a single solar tower, with energy storage capacity, to the California Energy Commission.

It’s possible the tower will be smaller than the 750-foot structure that was originally proposed.

It’s still unclear how Abengoa intends to finance the project, considering that it wouldn’t be built in time to take advantage of a 30 percent federal investment tax credit for renewable energy. Only projects that come online by the end of 2016 can qualify for the tax credit.

BrightSource executives said in September they dropped Palen largely because it wouldn’t have qualified, meaning they probably wouldn’t have been able to secure financing for its construction.

Abengoa indicated that while it hadn’t given up on Congress extending the incentive, it is no longer planning to rely on tax credits to help finance Palen.

“Abengoa, through its many financial capabilities, is looking at all options for financing while still hopeful for long-term tax credits that will aid continued development and deployment of renewable energy projects,” the developer said in a statement.

BrightSource and Abengoa originally proposed to build Palen with two solar towers, although the energy commission approved just one tower in its preliminary decision.

While the commission left open the possibility of later approving a second tower, Abengoa said it would follow the commission’s initial lead by proposing just one.

“The design and the work necessary to propose the amended project to the (energy commission) is underway,” Abengoa said in a statement.

“We expect to present the petition to amend to the (commission) in the first quarter of 2015 while leveraging all the work done in the last phase of the project.”

Under the original proposal, each tower would have been 750 feet high and had a capacity of 250 megawatts. Abengoa has not finalized the design for its new proposal, although officials said the single tower could end up being shorter than originally proposed.

Tower height has been a sticking point for some environmental groups, which have argued that Palen would be visible from wilderness and back-country areas in the southeastern part of Joshua Tree National Park, ruining a scenic vista.

David Lamfrom, associate director of the National Park Conservation Association’s California Desert Program, said last week that it would be difficult to pass judgment on Abengoa’s new proposal before knowing more about the height of any towers.

“We look forward to working with Abengoa to ensure that we can avoid many of the significant issues that were surfaced during the last Palen round, and to ensure that we’re putting projects in the desert that will help us do renewable energy and not harm our critical wildlife and our national park,” Lamfrom said.

Still, environmental groups are likely to oppose any proposal that Abengoa puts forward due to concerns about bird deaths.

In San Bernardino County, the Ivanpah solar project — the only other solar tower facility that has come online in the United States — has drawn controversy for killing hundreds, if not thousands, of birds.

Abengoa plans to build Palen with molten salt storage, the same storage technology in use at its Solana project in Arizona.

Molten salt storage generally involves using sunlight to heat liquid salt, which is then transferred to a storage tank. When electricity is needed, the molten salt is used to heat water, creating steam that can be used to turn turbines and generate electricity.

The Solana project uses parabolic troughs rather than solar towers, although Abengoa is currently building another tower project with molten salt storage in Chile. The first tower project with storage in the United States — SolarReserve’s 110-megawatt Crescent Dunes development — is set to come online in January.

Developing storage capacity is a top priority for regulators and solar companies alike, due to this intermittent nature of solar power and the problems this can pose for integrating solar power into the energy grid.

When the California Energy Commission issued its preliminary approval of Palen in earlier this year — reversing an earlier rejection — commissioners cited the potential for incorporating energy storage as the main reason they changed their minds.

BrightSource and Abengoa had previously said that financial barriers would prevent the immediate inclusion of storage at Palen.