Skip navigation

Appy hour: Smart phone apps save energy, money, time

Save energy with curly bulbs

The CFL Light Bulb Savings Calculator iPhone app by Yuan Ventures shows users the potential annual savings that can be realized by switching from traditional incandescent bulbs to compact fluorescent lamps (CFLs). To operate the calculator, simply select three values from the included list — your location, number of light bulbs to convert, and the wattage of the bulbs to be replaced. The calculator instantly provides an estimated annual cost savings based on the average kilowatts per hour your state charges. Download for $1.99 at the iTunes store.

Physics app offers refresher course on energy

Need a primer on the physics of energy, but hate to admit it? Simply download the Android app, Physics Help: Energy, from developer physicstutor1. The app contains a conceptual summary of energy plus a quiz covering 20 of the most basic questions on the subject, including potential, kinetic, and thermal energy, as well as work, efficiency, and conservation of energy. If you get stumped, don't panic: Instantly connect to thousands of Internet resources with a tap of your phone. Related physics reviews from the same developer cover electricity, motion, oscillation, force, and rotation. Each costs $1.09 at

App calculates building's energy performance

The 123ZeroBuild iPhone app from The Weidt Group is a free tool that calculates the performance of a carbon-neutral office building design. The application estimates the discounted payback for constructing a zero-emissions office building in any U.S. location. Use it to calculate the investment needed for photovoltaics to offset annual carbon emissions in your location. Payback calculations include estimated first costs for a highly energy-efficient building, photovoltaic costs, discount rates, and user-specified fuel escalation rates. Federal tax incentives are also figured in. Users may add local incentives that offset first costs to the overall calculation. Download it free at the iTunes store.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.