We’ve seen plenty of high-efficiency lightbulbs rolling around, but this new one — if it ever sees the light of day (groan) — has impressive potential. Cambridge University’s team of researchers are apparently quite close to bringing to production an LED bulb that can last up to 100,000 hours (about 60 years), and which — unlike some other eco-friendly lighting — contains no mercury. In the UK, where sale of some incandescents has been phased out, the team estimates they could reduce carbon emissions by about 40 million tons. The team has also significantly cheapened production by growing the LEDs on silicon wafers rather than the sapphire ones normally used, thereby bring the cost to… wait for it: $2.85. So when can we expect to see these badboys on the market? “Soon.”