Extension and Ag Research News


LED Light Bulbs Save Money

LED bulbs produce less heat and last longer.

When one small business in North Dakota switched from incandescent to light-emitting diode (LED) light bulbs, resulting in significant energy savings, the owners doodled smiley faces onto the electric bills being reviewed by an energy adviser.

The business replaced 100 65-watt incandescent bulbs with 8-watt LED light bulbs, which saved 5,700 watts of electricity while the LEDs produced the same amount of light.

“They instantly saw a huge savings,” says Russ Schell, owner of RJ Energy Solutions of Fargo, who advised the business toward more energy-efficient practices. “Their payback was within a couple of months.”

The business saved approximately $172 a month in lighting energy savings, according to Schell. The total savings was even more because air conditioning was not required to remove excess heat produced by the incandescent bulbs during the summer.

Other North Dakota small-business owners and homeowners also can discover energy savings by switching to more energy-efficient lights such as LEDs.

LEDs are a type of solid-state lighting with semiconductors that convert electricity into light rather than heat. They are at the top of the list of energy-efficient light bulbs available, even compared with compact fluorescent lamps (CFL), that curly version of the fluorescent light.

In order of efficiency, lights range from the incandescent, which lasts approximately 1,200 hours, to halogen to CFL to LED lights, which last approximately 50,000 hours.

When shopping for light bulbs, consumers should compare lumens, rather than watts.

“The quantity of light is measured in lumens,” explains Ken Hellevang, a North Dakota State University Extension Service agricultural engineer. “That 8-watt LED will have the same light output, or lumens, that the 65-watt incandescent had.”

The quality of light, or its color, is measured in a Kelvin rating. Lower numbers are more yellow, while higher numbers are a whiter or bluer light, Hellevang says.

Schell opted to advise the small business to install LED lights not only for their efficiency, but for other reasons. First, LED lights do not emit as much heat as an incandescent bulb.

“The savings by not needing to run the air conditioner to remove the heat produced by the incandescent bulbs is at least $70 per month,” Schell says. “Switching from incandescent to the LED lights resulted in 19,500 Btu (British thermal units) per hour less in heat output.”

The 100 65-watt incandescent bulbs produced 22,165 Btu of heat. The 100 8-watt LED bulbs produced just 2,728 Btu of heat.

“That’s a significant amount of air conditioning to remove that amount of heat in the summer in a business,” Hellevang says. “Adding all this heat from lighting really costs us because, in essence, we’re running a large heater inside the building, then a 1.6-ton air conditioner to remove that heat, so you have a double loss.”

Sometimes the heat can be removed with ventilation, but the ventilation may add humidity to the building, creating a cool, damp environment.

The heat from incandescent bulbs will assist with heating the building during cooler months, but often a more energy-efficient way is available to provide the needed heat.

In addition, not all CFL lights can be dimmed, and breaking a CFL emits a small amount of mercury.

LED lights, however, do cost more, at about $12 a bulb. Consumers should ask their utility companies about any available rebates to purchase the bulbs.

“Prices on the LEDs have come down, but there is still a significant price difference between a CFL and a LED,” Hellevang says. “However, if a person takes into consideration the labor and inconvenience of replacing light bulbs, that cost is offset by the longer life of an LED. The LED should have a lifespan of many years. That’s a significant thing for a small business to consider, even in homes, with elevated ceilings.”

LED bulbs don’t burn out. Rather, they decrease in light quantity and quality through time, so users should have a replacement schedule in place for the bulbs, Hellevang advises.

Additional information is available online from the NDSU Extension Service at https://www.ndsu.edu/energy to assist with selecting energy-efficient lighting.

NDSU Agriculture Communication - April 1, 2016

Source:Ken Hellevang, (701) 231-7243, kenneth.hellevang@ndsu.edu
Editor:Luann Dart, (701) 584-2172, luann@westriv.com
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