In Las Vegas, the big topic this week will be lights.

Lightfair International, the lighting industry's most prominent trade show, takes place May 12-14 in Las Vegas. Once a somewhat obscure trade event, the show draws more attention from investors and entrepreneurs these days because of the prominent role of lighting in achieving energy efficiency. Lighting consumes around 22 percent of the electricity in the U.S. and 25 percent of the total energy consumed in commercial buildings.

Worse, that energy is not consumed very productively or efficiently. PG&E estimates that only 1 percent of lights are networked in California commercial buildings. That means that lights that get left on stay on. (By comparison, computers and electronics only use 11 percent of the energy in commercial buildings.)

Some of the big lighting news this week:

--LEDs. Home Depot has begun to sell an LED bulb produced by Lighting Science that consumes around 9 watts but produces about the same amount of energy as a 40-watt bulb. It will sell for $19.95. General Electric has promised a similar bulb later this year, but it will cost $40 to $50.

Philips says it will top both of these companies with an LED bulb that can put out as much light as a 60-watt bulb. However, the Dutch lighting giant, which leads the market, has been notoriously silent when it comes to price. That might change this week.

Expect to see these bulbs, as well as bulbs from companies like Toshiba, Westinghouse, Osram and others, on display. LEDs initially will be aimed at the commercial market, but the consumer market is ramping up, as well. Many "neon" signs have actually been converted into LED fixtures (although we aren't sure about Vegas Vic here).

--Cost versus performance. While manufacturers are touting lower and lower prices, the key metric to watch is lumen output. That is, how much light the bulb actually puts out. I've been testing a Lemnis Lighting 60-watt/40-watt equivalent bulb. The light quality is great, but it really does function more like a 40-watt bulb than a 60-watter. Call it a 50 for now. (Lemnis is working on beefing up the performance.) Consumer feedback and reviews will be key in determining the winners and losers. A low price won't be everything.

Fixtures will have a huge influence on how these bulbs perform. Illumitex will show off its Aduro fixture which essentially directs more light from the LED toward where humans might be. Bridgelux has also developed LED packaging to boost output.

--Free and leasing. Although LEDs cost more than the average bulb, they last far, far longer. LED bulbs will keep on trucking for 15 years or longer, say advocates. Ergo, many companies will sell them under lease-to-own contracts. Ideally, the lease price will be less than the amount of power saved, making the bulbs free, says Warner Philips of Lemnis. Alan Salzman of VantagePoint Venture Partners has talked about how utilities could give away bulbs for free as a way to avoid building more power plants.

--Topanga Technologies will show off its plasma light and a street light lamp built for it at the show. Like Luxim, Topanga makes a bulb that generates light by exciting a plasma with radio waves. Plasma bulbs are only about the size of breath mints, but put out as much light as a street lamp. Nikolai Tesla championed plasma lights over 100 years ago, but the concept has only existed on the experimental fringes until recently. The big question now is whether plasmas can eke out a sliver of the market amid a push toward LEDs.

The U.S. Patent and Trademark office recently granted Topanga three patents. Khosla Ventures is an investor in the company, which has been in semi-stealth for years.

--Lunera, the only startup I know of that was founded by fashion photographers, will show off a series of lighting fixtures for LEDs, as well as an eBook device. Unlike many lighting startups, Lunera's secret sauce isn't in the light source. It is the fixture. Lunera puts the LEDs in its fixtures at the edge, rather than the center, of the lamp. The light runs parallel to the ceiling initially. It then gets channeled through wave guides and into a room. The indirect lighting technique eliminates glare and hot spots, CEO Mike Lesyna told us earlier this year. Light quality is also one of the touted benefits of edge-lit TVs, which use a similar design. The Westly Group is an investor.

"You would view ours as a sheet of light," he told us. "The trick is putting 100 or 1,000 in a ceiling and having them look all the same."

--More weird light sources. Konica, General Electric and a few others will trot out organic light-emitting diodes (OLEDs). OLEDs are flat devices that emanate their own light. Many high-end phones have OLED screens. In homes or offices, OLEDs could in theory cover a wall, turning the entire surface into a light fixture. Unfortunately, quality, durability and other issues still need to be worked out. (In that regard, keep your eyes open for Kateeva, which has come up with a system for producing OLEDs.) Also, a small version of the long-lasting fluorescent bulb from Lumiette is set to make its debut.

--Lighting networking will also make headlines. Some companies like Adura Technologies and Lumenergi have already begun to sell networking and dimming devices for fluorescent bulbs. Tube lights are still found in 85 percent of U.S. commercial buildings. Others, such as Digital Lumens and Redwood Systems, are meanwhile touting networks for tying LEDs together. These LED networks can also accommodate smoke detectors and other sensors and in effect become a nerve center for an office. Lighting networking will also be a big topic at The Networked Grid conference taking place the following week.

--Acquisitions. None may occur at the show, but you can bet it will be a topic of discussion at the bar. Philips moved to the top spot in lighting through acquisitions. Toshiba and TSMC have strongly hinted they will make acquisitions. Meanwhile, some startups like Luminus Devices have yet to take off into the stratosphere. In some ways, the show could be like a shopping spree.