The finder is among a barrage of green apps hitting the nation's smart phones and tablets. Last week, it won a green-app competition sponsored by the U.S. Environmental Protection Agency, besting 37 other submissions.
Even those in the industry know of no master list or clearinghouse for green apps, but they say that with increasing amounts of data from government agencies being made public, apps taking advantage of them are rolling out one after another.
A white paper released last week by Brighter Planet, a provider of carbon and energy calculations, noted that the world's data volume is doubling every 18 months.
In the past, said Andy Rossmeissl, cofounder of Brighter Planet, people had to rely pretty much on rules of thumb to make their sustainability decisions.
But in an increasingly complex world, rules of thumb don't always work. So, "either you make every single person in the world a climate scientist, or you use apps," said Rossmeissl. "Me, I don't have enough legal pads."
Apps based on reams of data can give individualized advice.
Brighter Planet developed a travel app called Hootroot, which got the runner-up award in the EPA contest.
I plugged in my home address, way out near Pottstown, and my office in Center City. Hootroot told me that driving would take 53 minutes (optimistic, I'd say) and result in the equivalent of 43.37 pounds of carbon dioxide being released. (It gave me no credit for having a Prius.)
Walking would take 10 hours, 56 minutes, but there would be no CO2 - except for what I exhaled on the trek.
Cycling would take 3 hours, 36 minutes. Again, no CO2. Hootroot took me down the Perkiomen and Schuylkill River trails - nice!
Supposedly, public transit would take me 2 hours, 15 minutes, but Hootroot didn't give me a route. It didn't say whether I should take a series of buses from Royersford, a train from Exton, or what.
Rossmeissl was puzzled because the app uses the Hopstop public-transit server; he concluded it was an anomaly.
When I specifically asked the app about Norristown to Philly, it steered me to the bus. From Conshohocken, it suggested the train.
The rules of the EPA contest were that the apps had to incorporate EPA data and be free for the next year.
While some apps seemed lame, there was also cool stuff. They map dirty-energy sites, water pollution, and air pollution. One maps "green" vehicle-service garages.
(See all of them and find out more at www.epa.gov/appsfortheenvironment/)
I consider myself a pretty savvy bulb-ologist, but I still enjoyed the Light Bulb Finder, developed by the sustainability technology company Eco Hatchery. With it, a user selects a fixture, then the style and wattage of the current incandescent, how many hours it's on a day, and more.
The app suggests an alternative, gives the price, and starts a shopping list. It tells you the payback period and tallies up how much you'll save over the bulb's lifetime.
This is no small matter. Lighting generally consumes about 15 percent of household energy, and Eco Hatchery estimates people can save $120 or more a year if they have better bulbs.
In my case, it found a CFL replacement for a three-way reading lamp that would save me $142 over its lifetime, although it would cost $18.47.
You can even have the shopping list e-mailed to you or shop through the app to buy the bulbs from Eco Hatchery.
Lighting is considered a "gateway" technology. Switch to better bulbs, and you just might decide to have a whole-house audit. The finder makes that easier, too; anyone in Southeastern Pennsylvania who accesses the finder will see a clickable banner steering him or her to the Energy Coordinating Agency, which has home-audit services.
Then again, I found the LED offerings slim, and the app pretty much limits its purview to bulbs from two companies, Philips and TCP.
But app cocreator Andrea Nylund said a shopper could take the list to any store, use the specs provided, and pick another company's bulb.
Also, she said they'll be expanding their bulb offerings as new ones come out and are tested by Eco Hatchery.
Get ready for the flood. All major lighting companies are coming out with new bulbs in response to energy-efficiency standards taking effect in stages, starting in 2012.
Contact staff writer Sandy Bauers at 215-854-5147, email@example.com, or @sbauers on Twitter. Visit her blog at philly.com/greenspace.