An A19 omnidirectional 8.5-watt LED on sale at Amazon for $21.28 from Lighting Science Group.

Lighting manufacturer Lighting Science Group announced yesterday it will begin selling low-cost LED lightbulbs on Amazon.com beginning today.

The company's A19 omnidirectional 8.5-watt bulb (40-watt equivalent) will sell for $21.98, and is only the first in a line of low-budget LED bulbs planned for sale at the online superstore, according to Lighting Science Group.

The company says its bulbs will last up to 23 years, and are 76 percent more efficient than a standard incandescent bulb.

"Lighting accounts for more than 18 percent of the average U.S. household's energy bill--that's because incandescent bulbs are essentially space heaters that give off a little bit of light," Lighting Science Group CEO Rich Weinberg said in a statement.

While it may sound steep, $21.28 for an 8.5-watt LED bulb is actually very reasonable. On Amazon, GE sells a 9-watt A19 omnidirectional bulb for $37.98, Feit Electric sells a 7-watt A19 LED for $29.99, and Philips sells its AmbientLED 7-watt bulb for $33.75.

In addition to the 40-watt, the company also plans to offer a 60-watt, as well as the smaller BR, MR, and PAR LED bulbs used for things like track lighting, flood lights, and picture lights.

And for today at least, some people may get a chance to try the bulbs for free. As part of its Earth Day launch on Amazon.com, Lighting Science Group is running a lightbulb giveaway contest on its Facebook page.