Plans to develop a free online service to give large businesses the ability to calculate how much solar energy they could harvest from their rooftops has gone better than expected.

The Denver Regional Solar Map, a product of the Denver Regional Council of Governments, or DRCOG, is now live at http://solarmap.drcog.org.

The tool allows anyone to plug in an address and find out the estimated solar potential of that building. The calculator gives an aerial view of a property, the total amount of electricity that a rooftop solar system could produce and the estimated annual savings on traditional electric bills.

While the project was originally intended to include information on only about 2,000 commercial properties, DRCOG was able to expand the study to include estimates for nearly 800,000 residential and commercial properties throughout the Denver metro area — including the vast majority of single-family homes.

“We were able to significantly expand the scope of the analysis that we did,” said Simon Montagu, director of customer resource and support for DRCOG.

The solar map was developed through a $180,000 federal grant through the Governor’s Energy Office, and utilized aerial photography, laser measurements and property records to figure out the size and solar capacity of individual rooftops.

While the system was intended to account for variables like shadows, trees and other obstructions in calculating true solar potential, officials at DRCOG decided it would be money better spent to broaden the program to include more properties, with a simpler estimate of solar potential based on property size.

“It’s supposed to get you interested,” Montagu said. “It gives you a pretty good starting point.”

A search of some notable rooftops in Boulder found astounding solar potential.

The Home Depot, located at 1680 29th St., for example, has the capacity to generate more than 6,000 kilowatt hours during summer months. A full-scale system could save about $65,000 a year off the company’s utility bill, according to the calculator.

Macy’s department store, located at 1900 29th St., has almost identical capacity, according to the online tool.

Boulder’s Municipal Building, located at 1777 Broadway, already has a solar system that’s rated at about 10 kilowatts and saves the city about $1,225 annually. But the solar calculator says the building has the capacity for a system 10 times that size, which could save taxpayers more than $13,000 a year.

The Camera building, located at 1048 Pearl St., has enough rooftop space to generate up to 20,000 kilowatt hours during summer months, and could save more than $19,000 worth of electricity each year with a 150 kilowatt system, according to the site.

The calculator includes a disclaimer that, given the current incentives and rebates available to subsidize solar systems, the optimum size of a large system is about 100 kilowatts.

The online program also offers links to solar rebate centers, as well as the option to fill out a contact card that is sent to local solar installers. The installers then contact the user to offer estimates and on-site inspections.

“It’s really meant as a connector tool,” said Jennifer Newcomer, a project manager for DRCOG who worked on the solar map. “We’ve had probably a dozen leads that have been generated just by people finding the site.”

Information from potential customers is passed on to members of the Colorado Solar Energy Industries Association.

Neal Lurie, executive director of the association, said the solar map would likely help the solar industry grow.

“There are many commercial building owners and homeowners who just don’t know where to begin,” he said. “We’re going to be able to make it easy to begin the process of going solar. Our hope is this will continue to strengthen Colorado’s presence in the solar industry.”

Boulder City Councilman Macon Cowles, who sits on DRCOG’s administrative committee, also lauded the program.

“It lowers the cost of solar energy companies by connecting them with customers and showing them the areas of the metro region where they can most efficiently do their work,” he said. “So it is good not only for carbon reduction, but also for job creation.”

Contact Camera staff writer Heath Urie at 303-473-1328, or urieh@dailycamera.com.