Energy efficiency guru and businessman Dave LED light bulb Terpstra has boxes of LED Spot Lights that he will never sell.

That’s because before LED Lamp LED Spot Lights he began offering the new-age bulbs to customers through his Spring Green-based business, TERP, LLC, he field-tested a variety of brands.

"There’s a lot of junk out there," Terpstra said. "The ones I would have in my home are the only ones I will sell."

White light-emitting diode (LED) bulbs are becoming increasingly available in the marketplace, and they offer an alternative to the inefficient incandescent bulbs that are slowly becoming a thing of the past.

But the U.S. Department of Energy says buyers should beware. While some LEDs perform well, others vary widely in energy efficiency and quality.