CFLs and LEDs: Comparison

The importance of lighting in our day to day lives never need be understated.

According to the Energy Information Agency (EIA), "in 2010, about 507 billion kilowatt-hours (kWh) of electricity were used for lighting by the residential and commercial sectors. This was equal to about 18% of the total electricity consumed by both of those sectors and 13.5% of total U.S. electricity consumption."

CFLs (Compact Fluorescent Lights) and LEDs (Light Emitting Diodes), today's two dominant alternative lighting technologies, offer consumers different sets of potential costs and benefits.

A quick review of both the on line and brick and mortar lighting markets shows that CFLs maintain a cost and light output advantage over their LED counterparts.

The LED market continues to lead in the energy efficiency and longevity categories.

Long and short term cost product comparisons provides another view of market trends. For example, at the current $10/bulb price range, consider two current consumer options.

Many retail outlets offer a version of a 40W CFL bulb (150W incandescent equivalent) advertising an average light output of 2,600 lumens and a lifespan of 10,000 hours.

In the LED category, that same $10 could get the average consumer a 6W (40W incandescent equivalent) bulb with an average light output of 300 lumens and a 25,000 hour lifespan. The cost of LED lights with a lumen output similar to the $10 CFL (in the 2,500 range) hover around the $100 mark.

Higher prices for CFLs and LEDs tend to damper general market trends. However, areas where utilities provide either CFL or LED customer rebates or discounts at local retail stores contribute to local spikes in retail lighting sales.

Consumers with a keen eye for bargains turn their attention to holiday offers. Over the past few years, local utility companies have used holiday season offers as an opportunity to introduce new customers to the technology by encouraging them to switch to LED holiday lights.

The future for LEDs only gets brighter. After forty years or so in development, scientists have continued to improve LED light output while lowering the final cost, in line with the often cited Haitz's Law on LED commercial development.

Within a decade or less, today's $100, 2,500 lumen LED, will price out in the $10 range.

Additionally, manufacturers continue to work on improving the temperature spectrum of LED light output. Both soft light or red light (typically measured in Kelvin terms as bulbs in the 2700K range or less) and day light, or blue light (typically measured in Kelvin terms as bulbs in the 3000K range and higher) LED options currently sit on market shelves, providing lighting choices for both residential and business consumers.

Commercial LED light applications abound, especially in areas such as specialty agriculture. Erik Runkle, associate professor and floriculture extension specialist at Michigan State University, assumes LEDs as the next big wave in greenhouse specialty crop production.

While light from both the blue and red areas of the light spectrum contribute to healthy plant development, a plant's need for red light during the blooming and/or fruiting phase, and the economic bottom line importance of that phase for commercial crop specialists explains much of the LED red light agriculture experiments ongoing today.

Using the red light spectrum to manage strawberry growth and fruiting, for example, could provide commercial growers an opportunity for a two crop/year yield rather than the traditional one crop/year yield.

Equally important, using different areas of the red light spectrum to manage bloom times for commercial flowers potentially helps commercial growers with the bottom line by decreasing production costs and and increasing flower or bloom yield.

LED contributions to the energy efficient homes of the future also start today. Speciality solar lighting products, from back yard patio lights to road side safety lights already anchor a growing market.

Looking forward, any lighting technology capable of reducing average energy use in the 15% range also moves the average renewable energy building (residential or commercial) closer to the aspirational net zero energy mark.

© 2011-2012 Patricia A. Michaels