By Peter Ellinwood
GreenPoma.com

Energy saving light bulbs are more sophisticated than traditional bulbs. Inevitably, that means they cost more. But since they also use less electricity and last longer, they save money and reduce air pollution and landfill waste over time -- some would say they even make you money down the road. So how do you determine if a more expensive energy saving bulb is a smart investment?

Using current electricity rates and daily "burn time" assumptions, the annual cost per watt of electricity for residential customers in New England can be calculated. So to determine payback, you simply factor in the watts saved by an energy efficient light bulb, along with its price.

Here’s an example: if you switch from 100-watt old-fashioned bulbs to 23-watt CFLs (compact fluorescent lamps) in two table lamps next to a sofa, you’d be saving 154 watts per year. Here's the math: each bulb saves 77 watts (100 watt standard bulb minus 23 for a CFL), so 2x77 = 154 watts.

Now suppose these lamps are routinely on every evening for 3 hours. Using the table below, which shows current energy costs in both Maine and New Hampshire, assume that a watt in New Hampshire costs 18 cents a year. So $0.18 x 154 watts = $27.72 in annual savings.

And that’s just for two small light bulbs in your living room!

That means you can buy a pair of quality CFLs for $8, your electricity savings will pay back your investment in less than four months. If these bulbs have an average rated life of 12,000 hours, you’ll still have thousands of hours of life remaining after payback, during which you’ll boost the return on your $8 energy efficient light bulb purchase every time you turn on your lamps.

Now just imagine the savings if you put CFLs throughout your house. Something to think about….

Peter Ellinwood is a green lighting expert and owner of GreenPoma.com in Concord. He joined the Green Alliance last year as the first Business Partner to join from Concord. Click here to learn more about his business!