It has been known for a long time that the Earth's oceans contain traces of uranium, a radioactive substance often used in nuclear power plants to power cities. On the other hand, extraction methods for getting uranium out of the ocean has never really been that cost effective.
We've tried using special kinds of plastic strands coated in chemicals that have negative charges to attract the positively-charged uranyl particles in the ocean and then collecting them to take the bounty before repeating the process over and over. On the other hand, new methods developed by Stanford researchers could make the process much more cost effective.
Instead of using plastic, the Stanford team utilizes special carbon nanotubes and electrical pulses, which happen to attract a lot more of these uranyl particles. It turns out that this method draws more than nine times the amount of uranyl in the same amount of time, making this a potentially useful method of collecting uranyl particles from our oceans.
With all of the uranyl that's just passively floating around in our oceans, and all the additional uranyl that makes it into our oceans as time goes by, harnessing this uranyl could provide power to the planet for a solid 10,000 years to come.
Current methods of collecting uranium don't involve the ocean at all; rather, we mine for it in quarries where the stuff is plentiful, such as in Australia, Canada, Kazakhstan, and Russia. On the other hand, some day we will run out of uranium from these plentiful sources and will need to look for alternative sources.
Since the ocean is always being fed uranyl particles from the rocks the ocean waters smash up against, it seems the ocean can do all the work of 'mining' for it and all we have to do is sit around and passively collect it from our oceans.
Could this actually be a limitless source of nuclear power? "Limitless," probably not, but very sustainable? Likely!