New device can make hydrogen when dunked in salt water
Enlarge / The right membrane can make hydrogen production much easier. (credit: Andriy Onufriyenko)
With renewable energy becoming cheaper, there's a growing impetus to find ways to store it economically. Batteries can handle short-term fluxes in production but may not be able to handle longer-term shortfalls or seasonal changes in power output. Hydrogen is one of several options being considered that has the potential to serve as a longer-term bridge between periods of high renewable productivity.
But hydrogen comes with its own issues. Obtaining it by splitting water is pretty inefficient, energy-wise, and storing it for long periods can be challenging. Most hydrogen-producing catalysts also work best with pure water-not necessarily an item that's easy to obtain as climate change is boosting the intensity of droughts.
A group of researchers based in China has now developed a device that can output hydrogen when starting with seawater-in fact, the device needs to be sitting in seawater to work. The key concept for getting it to work will be familiar to anyone who understands how most waterproof clothing works.