Engaging Energy

Superconductors have been around in the labs for decades now. They have been a mainstay of high-end scientific research and niche medical applications for decades, but on the industrial scale they have always been a bit to expensive to run in mass market applications, like the energy sector. Theirs has been a story of potential energy efficiency boosts, power savings, zero transmission losses and all the first order energy system changes that no-one is against. Its time to take a look at them a little closer since I dismissed them so off-handedly in my previous post regarding the North Sea super grid.

Crash course
Superconductivity was discovered 99 years ago.
Different materials become superconductors at different temperatures.
HTS (High Temperature Super-Conductors) are defined as having a transition temperature above 30K (-243C), and the highest temp superconductors have a validated operating temperature around 135K. The boiling point of liquid nitrogen is 77K, so this has made HTS much more accessible and practical as nitrogen is commonly used as a liquified gas.
However, recently an HTS material that operates at 254K (-19C) has been claimed. This would clearly be a massive leap forward as standard compression-cycle refrigeration techniques could be used rather than immersion in liquified gas. Obviously these are lab findings and there is no guarantee that production of these materials could be scaled up to industrial quantities (they use some relatively commonplace elements, so there shouldn’t be any resource availability problems for once). The standard 10 years+ from first publication warning applies here i.e. no field application will arise from a lab discovery within 10 years of first publication.
So industrially we are looking at the 135K materials, which is still OK, but not the massive jump that we’d all like to see.

Energy Applications
Cabling – Zero transmission losses over long distances, or high capacity transmission without the current massive infrastructure (overhead pylons) are the main lures.
Power:Weight improvements – instead of copper conductors, using HTS in motors greatly increases their power:weight ratio. The applications in electric vehicles are obvious, so I won’t labour that point, but also consider all those static motors in air-conditioning units, factory assembly lines, and my personal favorite the conveyor belt. The infrastructure to hold these in place could be smaller and lighter, their maintenance quicker and safer as well as their operating costs lower.
For ‘motors’ also read ‘generators’ and you see the application for wind turbines and other renewable generating technologies. Smaller lighter nacelles means smaller lighter towers, means cheaper generating capacity and lower maintenance costs.

Renewable Energy Focus has done this two parter (Part One & Part Two) which covers all these much better than I ever could. You’ll need to subscribe for free to access the full articles, but its worth it.

The take home from these two articles is that super conductors should be on the shopping list of industry. I was too quick to dismiss them for the North Sea grid. With 150 times the carrying capacity per unit weight and 1/3 of the transmission losses superconducting cabling should be the first option for mega projects, not the last.
When/if those properly room temperature super-conductors reach the supermarket shelves a revolution will take hold.