Advantages of Hydrogen Gas When Compressed into a Metal - A Holy Grail?

Using two diamonds, scientists squeezed hydrogen to pressures above those in Earth's core -
(Sang-Heon Shim, Arizona State University) (Courtesy from www.sciencemag.org)

Scientists have already made liquid Hydrogen metal, the substance thought to form the interior of giant planets like Jupiter—by ramping up pressure at higher temperatures.But Isaac Silvera and his colleagues from Harvard University wanted to work at low temperatures and transform hydrogen into something still more exotic; a solid metal.

At cryogenic temperatures, hydrogen is a liquid. As the pressure rises, the liquid quickly becomes a nonmetallic solid (see diagram, left). In 1935, Princeton University physicists Eugene Wigner and Hillard Bell Huntington predicted that beyond 25 GPa, the nonconductive solid hydrogen would become metallic. But experimentalists passed that threshold decades ago with no sign of a solid metal.

Silvera and Dias claim they've pushed their cell into an unexplored realm of low temperature and extreme pressure, succeeding in part because they avoided continuous high-intensity laser monitoring that they say can also cause an anvil's diamonds to fail. Eventually, as they neared 500 GPa, the black sample became shiny and reddish. A low-intensity infrared laser—one that wouldn't risk stressing the diamonds—revealed a strong spike in the sample's reflectance, as expected from a metal. Only then did the Harvard pair use a different laser, in a procedure called Raman spectroscopy, to verify the peak pressure in the diamond cell.

Diamond vise turns hydrogen into a metal potentially ending 80-year quest from Ashok Kumar

Advantages of Metallic Hydrogen:

1. Metallic Hydrogen acts as "SuperConductor" at room temperature which can save a lot of money and energy. Most of the current superconductors work at as low as -269 Degree Celsius.

Superconductor exhibiting magnetic levitation. (Image Credit: Department of Theoretical Physics at Ural University)

2. It can be used as a rocket propellant at a very low cost.

3. It can be used as a material in MRI Scanning to make it cheap. 

4. It can also be used in power cable and price of electricity could be dragged down. 

and more probably there is an entire chance of new greener technology could be implemented, especially in the area of renewable energy resources... this could be a "Holy Grail".

(Video Courtesy by: TechInsideUK)