In nearby Wallingford, energy efficiency aficionado David Director is ecstatic about the new bulbs.
He cruises the lighting aisles, and if the price is right - more and more often, it is - he'll buy a new one and try it out.
He's even started replacing CFLs that aren't burned out yet with LEDs. "It's part of the experiment," Director said. So far, the lights are "very, very satisfactory."
And so the battle of the bulbs rages.
As conservatives and self-avowed curmudgeons rail at what they see as excessive government oversight, energy efficiency advocates hail a new era of lighting, one they say has been a long time coming since Thomas A. Edison's famous invention 135 years ago.
Either way, the standards will likely change forever the way we think about - and measure - lighting.
Instead of watts, we'll soon start referring to the actual light output, or lumens, of a bulb. We'll become conversant in the "color" of light.
It all began in 2007, when Congress added lightbulbs to the growing list of appliances - from refrigerators to air-conditioners and clothes washers - subject to efficiency standards.
The Energy Independence and Security Act mandated that bulbs of the future use 25 percent less energy than typical incandescents.
It wasn't just about using less energy. It was also about spending less money. The Department of Energy estimates that even though the newer bulbs may cost more at the outset, replacing 15 traditional incandescent bulbs could save a family about $50 a year, given the lower electricity use.
The standards went into effect for 100-watt bulbs on Jan. 1, 2012. The next year, 75-watt bulbs came under the law.
As of Wednesday, 40-watt and 60-watt bulbs must meet the new standards.
Many still mistakenly - or belligerently - refer to the standards as a "ban" on incandescents.
Incandescents are still with us. But they're filled with halogen, so the filament burns efficiently.
"You can still buy any bulb you want, as long as it meets the standards," said Noah Horowitz, director of the Center for Energy Efficiency at the Natural Resources Defense Council.
As supporters of the legislation hoped, the standards spurred innovation.
CFLs, once reviled for their yellow hue and slow start-up, have improved. Today's CFLs also use significantly less toxic mercury - a sticking point for many consumers.
And LEDs - considered to be the leading contender for bulb of the future - have lost their bluish tinge and gotten brighter. Some are even dimmable.
"There's been more innovation in the past five years than in the past 100," Horowitz said.
Plus, "the prices are dropping faster than we ever imagined, with more to come," he said. Several LED bulbs now break the $10 barrier.
Still, adoption has been slow. Horowitz estimates that three billion sockets in the United States still have inefficient lightbulbs screwed into them, a figure that has not changed dramatically in recent years.
But Marianne DiMascio, outreach director at the nonprofit Appliance Standards Awareness Project, predicts that will change, given this year's expansion of the standards to America's most popular bulb - the 60-watt.
Horowitz said that once adoption takes off, savings could accumulate quickly. "Once we get an efficient bulb in those sockets, we'll cut the nation's electric bill by about $13 billion a year," he said. "That's 30 large coal-burning plants worth of electricity."
Osram Sylvania conducts annual "socket surveys" to measure public attitudes about lighting, and its latest results were announced in December.
Based on 300 interviews, it showed that most consumers (64 percent, up from 52 percent in 2012) were aware of the efficiency standards for bulbs. But few knew that they would apply to 40- and 60-watt bulbs as of Wednesday.
Most - 92 percent - say brightness is the most important factor when making lighting choices. Energy usage and price are tied for third on the priority list, after life span.
Many consumers want U.S.-made bulbs, which are tough to find. But Horowitz and others say some manufacturers have expanded their U.S. operations. They include a Sylvania plant in St. Marys, Pa., where the guts of halogen incandescent bulbs are made.
Most consumers say they plan to switch to more efficient lighting.
In Southeastern Pennsylvania, Peco has been funding discounts for some CFL and LED bulbs at area stores as a way of meeting state energy efficiency goals.
So far, more than 7.6 million bulbs have been purchased under the program, and the company projects that enough money is in its program to continue the discounts through May 2016.
However, a third of the survey respondents say they'll stock up on incandescents.
The federal legislation applies to the import and manufacture of bulbs. So stores and others can still sell traditional incandescents while supplies last.
Several companies sell them on Amazon, and in the comments, one buyer recently posted a mock obituary of the traditional 100-watt incandescent:
"He will be remembered fondly for his warm, homey glow, his gentle cooperation with dimmer switches, and his flexibility and usefulness in all indoor-and-outdoor light fixtures. He had a simple, aesthetically pleasing design, so iconic it became known as the very symbol for ideas."
Halogen incandescent bulbs: These use 28 percent less energy than their predecessors. While cheaper than CFLs and LEDs at the outset, they use more electricity and last only one to two years.
CFLs: These are the swirly bulbs. A 20-watt bulb puts out as much light as a 100-watt incandescent, and they last about 10 years.
LEDs: This is, overall, the cheapest option because of its long life (up to 25 years) and low energy use. CFLs and LEDs use about 75 percent less energy.
The Federal Trade Commission has required new labels for bulbs, including estimates of their annual electricity cost. Be sure to get a bulb that's as bright as you need. If you are replacing a 100-watt bulb, look for one that gives 1,600 lumens.
Most people prefer a "warm white" bulb. Many don't like the blueish quality of a "daylight" bulb.
Pick a bulb with the "Energy Star" label, indicating it has met specifications established by the U.S. Environmental Protection Agency.
Source: Natural Resources Defense Council