Energy Efficient Light Bulbs

The US Environmental Protection Agency (EPA) developed the ENERGY STAR program in 1992 and has since partnered with the US Department of Energy (DOE) to promote energy efficiency.  The ENERGY STAR label is used on products that meet the energy efficiency standards of the program and may be found on major appliances, office equipment, lighting, home electronics and more.  Home-builders can also design and build homes to EPA standards, earning the ENERGY STAR label after inspection and certification.

One of the easiest ways to reduce household energy consumption is to replace traditional incandescent light bulbs with energy efficient light bulbs.

Triple E Agent Assignment:
Examine the return on investment for energy efficient light bulbs, and run test by monitoring single family home electricity consumption...

Is there a noticeable impact to electricity consumption after making these changes?


ENERGY STAR rated compact fluorescent lights (CFL) are most abundant on the shelves with an increasing number of light emitting diode (LED) technology options.  DOE is trying to enforce energy efficiency standards that would, in essence, phase out incandescent bulbs in favor of CFL, LED or other more efficient lighting technology.  Not without debate or opposition, this effort is another step that relates to the Energy Independence and Security Act of 2007.

In many cases, a lower wattage CFL (11W or 13W) 'bulb' is designed to replace a standard (40W or 60W) incandescent bulb.  So, in theory the operating cost is about 1/4 the cost of an incandescent.  There is, however, a substantially higher purchase price for CFL versus incandescent.  On the other hand a CFL has a much longer life than incandescent by, for example, 7 to 11 years.  Trent Hamm does a great job of running the numbers on these three lighting options, in this article.  In summary, Hamm's total cost estimates are:

• Twelve 60W incandescent lights used for 10,000 hours would cost ~$918.90
• Twelve 13W CFL used for 10,000 hours would cost ~$219.90
• Twelve 7W LED used for 10,000 hours would cost ~$172.75

Triple E recently replaced 6 incandescent 60W bulbs with 13W CFLs.  This was a follow-up to  Household Energy Use, where more substantial changes were made regarding heating/cooling and ventilation.  Several of the replaced lights were/are exterior lights that are on from dusk til dawn.  All other electrical usage during the nighttime hours remained fairly consistent in the before/after phases.

• Before: baseline usage was 0.75 to 0.86 kWh per hour or $0.09 to $0.10 per hour.
• After: baseline usage is 0.45 to 0.69 kWh per hour or $0.05 to $0.08 per hour

Clearly there is a decrease in energy usage, though in this uncontrolled experiment it is difficult to say exactly how much.  There are a few issues with CFL or LED that may make the conversion somewhat problematic.  Including:

• initial purchase price
• light/color difference
• difficulty finding appropriately sized CFL or LED for small 'candelabra' type fixtures
• 20 to 30 second delay for full illumination of CFL
• mercury contained within CFLs requires coordination of safe disposal through local municipal solid waste or recycling facilities

Regardless of these or other obstacles, there are benefits on the energy consumption, environmental, and economic fronts for those that convert to energy efficient light bulbs.

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Triple E.