Over the years, people have tweaked and improved almost every invention ever made. However, the humble incandescent light bulb, has seen very little change since Thomas Edison tweaked the design in 1879.

There have definitely been some half-hearted attempts like the compact fluorescent light bulb and also a more efficient version of the incandescent light bulb.

However, they have either been too expensive or just do not live up to the standards set by the regular bulb.

Now the U.S. Department of Energy (DOE) is sponsoring the L-Prize, a $10mm USD contest for the company or individual who can invent an ultra-efficient version of the 60-Watt incandescent light bulb. Two additional $5mm USD prizes have been allocated for the inventors of an energy-efficient LED reflector lamp and a new 21st Century Lamp.

Surprised at the size of the prize? You won't be if you realize Americans use 425 million incandescent bulbs annually. If these are replaced by more efficient LED bulbs, it would not only save enough energy to light up more than 18 million homes, but also, cut carbon emissions by 5.6 million tons annually!

Added to this is the fact, that new energy laws coming into effect by 2012, will result in completely banning the use of the current incandescent bulb.

However, it is not easy to win the prize money. The DOE has laid down some pretty stringent rules for the entry to be eligible. The new bulb has to be able to provide the same amount of illumination that a 60-watt bulb provides, but utilize only 10-watts of energy. It must also last 25,000 hours - 25 times more than our current bulb and, over 75% of the parts or manufacturing has to be done in North America.

So far, they have only one entry - Netherlands based Phillips Co, recently submitted 2,000 prototypes, which they say meet all the criteria. It will however, take a year of extensive testing before the DOE will announce its views on the bulb. Meanwhile, they are hoping that some other big companies or smart individuals will step up to the challenge too!

sources:osa-opn.org,lightprize.org