In what organizers see as a race against time, two Vashon groups are looking for publicly owned sites for their ambitious community solar projects — efforts triggered in part by generous state incentives slated to end in 2020.

Vashon Community Solar, a project spearheaded by The Backbone Campaign, announced its intention to launch a broad-based solar-investment project at an Earth Day celebration at Vashon High School earlier this year. The group initially thought it would place a solar array on one of the school district buildings, but engineering issues as well as the group’s need to move quickly made none of the school district’s sites ideal, said Bill Moyer, director of the Backbone Campaign.

Vashon Community Solar now hopes to erect a $400,000 to $500,000 project on a sloping parcel next to the King County transfer station on Vashon’s west side, a project that would be funded by investors kicking in $1,000 or more.

The group has contracted with Carol Eggen, a former airline executive who has a solar array at her own home, to try to get the project off the ground. Discussions with the county are currently under way, Eggen said. There’s a chance, she added, that the group could have its project erected by next spring, in time to begin taking advantage of the solar energy that comes with longer days.

A new effort, meanwhile, is also gaining traction — this one spearheaded by Vashon architect Gib Dammann, who had initially joined forces with Moyer on Vashon Community Solar. Called Vashon Solar LLC, Dammann’s group is based on a simpler financial model and will likely have fewer investors, each of whom will be asked to invest $5,000 or more.

Dammann, who is working with Islanders Evan Leonard and Holly Goddard on the project, has begun talks with Vashon Island Fire & Rescue about placing an array on its maintenance building behind the Penny Farcy Training Center on Bank Road. He, too, hopes to have a project up and running by spring.

Both Moyer and Dammann said there’s room for two community solar projects on Vashon. Indeed, both men said they hope to see several such projects on the Island over time. Moyer, however, expressed some frustration about the two similarly named efforts taking place simultaneously.

“It seems a little confusing. It’s not what I prefer,” Moyer said.

Dammann, for his part, said he has high regard for what Moyer’s attempting to do but felt that the project was going too slowly and that the financial model — involving possibly hundreds of investors — was too complex.

“I have contended all along that we should start with a simple model and move up,” he said.

But, he added, “I don’t want any of my comments to be construed as criticism. There are two community projects that are going to happen on the Island, and there are differences between the two. … I think there’s a need on this Island to have multiple choices.”

Community solar projects are taking place in communities across the state and around the country, most of them driven by tax and financial incentives offered by the government in an attempt to jump start the fledgling solar panel manufacturing industry and bring more green power into the grid.

A federal tax credit gives each investor a 30 percent construction refund for various green energy projects, meaning that an investor who provides $1,000 toward the project can reduce his or her tax bill by $300, Eggen said.

The state Legislature, meanwhile, sweetened the pot with a bill it passed two years ago in an attempt to stimulate a solar panel manufacturing industry in Washington: For every kilowatt hour produced by a system manufactured in the state and placed at a public building, the entity that created the project receives $1.08 — or 10 times the market value of the electricity — to be divvied up among its investors.

The project Vashon Community Solar hopes to place at the transfer station could garner close to $60,000 annually in such payments, Eggen said. The subsidy, however, is slated to end in 2020 — part of the reason both Vashon projects are moving quickly to get systems installed.

Finally, the public agency hosting the array also has an incentive: A decent-sized array could save the agency $5,000 or more a year in energy costs, Eggen said.

The federal incentives have gotten some criticism recently. A New York Times story published earlier this month found that many of the federal subsidies are going to large companies with considerable resources.

But the community solar projects are a different kettle of fish, supporters note. The maximum return any one investor can receive in incentive checks under the state program is $5,000 per year. As for the federal tax credit, individual investments are capped at $35,000 — meaning the largest tax liability reduction an individual could receive is $9,000.

As Dammann noted, few investors on Vashon have the kind of wealth that would enable them to take advantage of such a write-off. “At this point,” he added, “there’s a limited number of investors.”

A survey the Backbone Campaign conducted, Eggen added, found that most of those interested in the community project were motivated only partially by financial considerations. “Far and away, the major reason for people to do this is for environmental reasons,” she said.

But community solar projects cannot start garnering investors until they first find a site, and on Vashon, that’s been a stumbling block, Eggen and Moyer said. “It’s surprisingly frustrating and difficult,” Eggen said.

The site has to have good sun exposure and be oriented a certain way. What’s more, Eggen said, the array should be in a high-profile location, acting as a kind of advertisement for the power of the sun.

Moyer had hoped to put an array on a roof at a school district building, but engineering issues made it impossible at Chautauqua, McMurray and the high school gym, he said. The new high school, meanwhile, will likely be designed with solar panels in mind, but the project won’t be completed until 2014 — a delay neither group can afford in light of the 2020 end to state subsidies.

Moyer and Eggen, however, say the transfer station looks promising. Eggen met with a top county official and Artisan Electric at the site earlier this week and was encouraged by their comments — particularly the amount of sun exposure the site receives. The county has yet to partner with a community group to install solar, Eggen said, and there are many layers of review that such a project would need to go through, but early indications are good.

“The county says they’re really keen on this,” she said.

Dammann, too, is optimistic about the fire department’s maintenance building. He made a presentation to the fire commissioners two weeks ago about a potential partnership and was well-received. “We’re really anticipating that this is going to work,” he said.

Rex Stratton, who chairs the fire commissioner board, concurred. “It’s a great idea. I’d love to see us use one of our buildings in this manner.”