Energy Efficient Light Bulbs: Estimating Your ROI

If you want to consider an LED bulb for your fixture, you'll get even better efficiency and longer life. For a 60-watt replacement, one popular choice right now is the Philips 12-watt Ambient LED, which produces remarkably soft, yellow light. It's also fully dimmable, and is rated to last 25,000 hours. It costs $40 upfront, which we know is more than you're used to spending on a bulb. But let's calculate potential savings.

For a lamp that's on six hours a day, that would give us 12 watts x 6 hours x 365 = 26.3 kWh. At $.12 per kWh, that's $3.12 a year to operate. Subtract that from $16, and that's a savings of $12.80 a year. With a lifespan of 25,000 hours, it should theoretically last for about 12 years in this application. Over 12 years, we would otherwise have to buy 24 incandescents, for a cost of $18, or about $1.50 each year. With the annual savings of $12.80 in energy and $1.50 in bulbs, the LED will pay for itself in just under three years.

That's not bad, when you consider that many upgrades take longer than that (solar panels, a geothermal system, a wind turbine, a hybrid car), and most things we buy never pay for themselves at all. For years, you'll enjoy high quality light and you won't have to worry about changing bulbs or disposing of harmful materials.