Solar energy is more accessible to Americans than ever before. There are federal tax credits, cheaper photovoltaic systems on the market and hefty rebates that make a return on investment more attractive.

But sifting through this stack of information can be daunting, so city sustainability officials are simplifying the process by rolling out solar maps—online, interactive one-stop shops. Think Google Maps for solar.

“This is a way to make it much more tangible for the public,” said Tria Case, university director of sustainability for the City University of New York (CUNY), which partnered with New York City to create its solar map, set to launch early 2011. “The more we can streamline the process, the greater the likelihood we will see an increase in solar in the city.”

New York is the latest city to be developing a comprehensive map, but San Francisco started the trend in 2007. Boston was a year later. Since then, a slew of other major cities have unveiled maps, including Los Angeles, Portland, Ore., and most recently, Salt Lake City and Denver.

Since the tools — which provide data such as solar potential, cost and energy savings — went live, PV installations have gone up. San Francisco had 554 solar installations in 2007 when the map launched. Today, that number is 2,073, with a total capacity of 11 megawatts. Boston started with about 350 PV projects, with about a half a megawatt installed, in January 2008. The city has since installed 3 MW, and has a goal of 25 MW by 2015.

But how big a role the maps play in the increase remains to be seen. Incentives — which some say are the deciding factor — may be ubiquitous but aren’t permanent.

A Magic Bullet?

The maps, many of which are partially financed by the U.S. Department of Energy’s Solar America Cities program, have undoubtedly simplified the process of researching solar. After entering an address, users are presented with a bird’s-eye view of the location and a box with tailored information, including roof size and solar potential of the home or business. Cost and energy savings also pop up, with a list of installers and incentives just a click away.

San Francisco developed the first solar map with Critigen’s SAFE methodology, which uses a combination of aerial imagery and 3D modeling with an emphasis on sun and shade and obstructions to determine a building’s solar potential. The other information is pulled from various city, state and federal websites and databases, essentially an aggregate of incentive information that is uploaded into the technology. (See screenshot of the map, right.)

“We wanted to make it easier for people to understand the technologies, costs and available incentives by providing this one-stop resource,” said Danielle Murray, renewable energy program manager for San Francisco Department of the Environment, which worked with Critigen, a sustainability offshoot of the environmental and engineering consulting firm CH2M HILL. Critigen developed many of the solar maps for cities, including Anaheim, Calif., Berkley, Calif., Los Angeles and Portland, Ore.

“[The tool] is definitely playing a big part in increasing solar installations,” Murray said. But it’s not the magic bullet, she added. The state and city’s municipal incentive and the department’s outreach program, GoSolarSF, is another key factor in the four-fold increase in solar installations San Francisco has experienced since mid 2007, she said.

“We’re lucky here,” said Murray, referring to the local and state opportunities. California has had some of the best—and consistent—incentives for solar for years, even before the American Recovery and Reinvestment Act (ARRA) passed. ARRA awarded tens of millions of dollars to local governments and the private sector to boost residential and commercial solar installations by way of tax credits, grants and rebates.

In Boston, though, the increase in solar installations is more tied to what’s available incentive-wise than the online tool. “It’s an effective marketing tool that creates buzz and gets people interested in solar,” said Andy Belden, the Solar Boston coordinator. But, he added, you can’t really point to the map as the reason more people are installing solar.

The city’s $68 million Commonwealth Solar fund, which launched in January 2008 when Boston’s solar map was unveiled, was expected to last four years but ran out of cash in fall 2009. In response, an additional $8 million in ARRA funds were awarded to the city for a new solar program. That money started to roll out in summer 2010. Waxing and waning of installations and the availability of the rebates coincide.

“When the rebate died, installations went down,” Belden said. “And now with the [Solar Renewable Energy Credit] program, installations went up.”

The Denver Regional Council of Governments (DRCOG) opted to keep cost information out of the tool for this reason. “There’s volatility in the incentive market,” said Jennifer Newcomer, a socioeconomic analyst for DRCOG. “The installers should have that conversation.”

Denver’s tool lists solar energy output, savings and a form to submit to installers in the area to request service.

Mimicking Success

In the last two months alone, several major cities have unveiled new maps. Denver’s map launched in November, and Salt Lake City unveiled its map in October.

And soon, the Big Apple will reveal its solar map, which is being developed by CUNY’s Center for Advanced Research of Spatial Information. Data was captured using Lidar, or Light Detection and Ranging, technology by the Sanborn Map Company, which flew serial missions over the city at night, zapping lasers to collect precise images.

“It’s really about education,” CUNY’s Case said. Some people hear solar and think it’s expensive, she said, but the tool shows them the individual steps to get solar and calculate its true value.

Much of the support for these tools, including New York’s, a Solar America City, comes from the DOE. About half of the designated 25 Solar America Cities now have or are in the process of getting a solar map. And some of the projects were funded in part through the Recovery Act. New York, for example, was awarded $200,000 to develop its solar map. Berkeley, Calif., used $55,000 in granted funds for its map.

“It’s about exposure,” said Ted Quinby, project manager at the National Renewable Energy Laboratory (NREL) for the Open PV Project, a national solar map that tracks installations and gives real-time status of the solar photovoltaic market. “It shows that PV is viable and mainstream. The more you publicize it, the more consumers will sign on to do it.”

These maps, including NREL’s national one, are essential, he said, because they give a basic understanding of where PV is growing. The solar maps also track installations. On sf.solarmap.org, hundreds of yellow, blue and purple dots representing homes, schools and businesses with solar are splashed across the map when users input their projects.

“The map itself will show people what their neighbors are doing,” said Sara Baldwin, a senior policy and regulatory associate for Clean Energy Utah, which partnered with Salt Lake City County to launch its map. “It might intrigue people to know that certain areas have solar over others. And maybe it will help dispel the myth that solar is only for upper class neighborhoods.”

A Sunny Future

Salt Lake City has a goal of installing 10 MW of solar capacity by 2015, an ambitious one for a city with relatively few installations. The city and county, however, are hoping that the tool will help make it a reality. A marketing campaign for the new map was launched in the months prior, touting family values and job creation as key factors in switching to solar. (See screenshot, left)

“Solar: A New Family VALUE” billboards, featuring a family of four were put up throughout the county, along with ones that read, “Solar Works for Utah.” The sign depicts three men in construction hats with bright orange safety vests installing rooftop solar panels. Both list the URL to the map.

“I think in the future, we would like to make this as user friendly as possible to ensure that doesn’t sit on the virtual shelf,” Baldwin says. “We want it to continue to be an active and updated website.”

The remaining cities also want to evolve, improve and build upon the maps: tracking wind potential, carbon footprints and water usage were all ideas thrown around by people close to the project. Officials involved with the solar map projects said the tools will continue and remain relevant, even if incentives fizzle.

Also, solar panels are becoming cheaper as more Americans seek to live sustainably. Solar module prices dropped 37 percent in 2009, according to iSuppli, a market research firm. In 2010, prices dropped another 20 percent, and iSuppli forecasts that solar system prices will continue to drop in 2011 and 2012.

“It’s both aspects,” said Quinby, referring to the cost and the solar maps affecting installations. “But if we didn’t have the tools around, I don’t think we would have as many people researching it.”