Superconducting Magnetic Energy Storage (SMES)

[MattR]

I cam across SMES (Superconducting Magnetic Energy Storage) while researching superconducting and had a few questions I'm hoping to have answered.

1. I have read that SMES devices are primary used in the event for short interruptions in power, and aiding in efficiency in the power grid. Can a SMES device be used like a back up battery in the event of a power outage similar to a back up generator kicking in? Considering some can hold MWH worth of energy I would think that if power went out the SMES device could kick in and provide the back up power needed until it was depleted or the power was restored.

2. Since SMES use superconducting in a way similar to an MRI (superconducting loop) to create a magnetic field to store energy do they loose any of that energy? If so, how much and over what time frame.

3. Do SMES devices need to be ramp-up, again similar to an MRI to reach a field strength or is that irreverent?

thanks for the help,
Matt R.

 

[anorlunda]

Welcome to PF Matt. We prefer it if you include a link to what you have been reading. Please post the link before we answer.

 

[Dale]

Since SMES use superconducting in a way similar to an MRI (superconducting loop) to create a magnetic field to store energy do they loose any of that energy? If so, how much and over what time frame.

They do not lose energy; there is no resistance. However, it does require energy for the refrigeration to keep them at superconducting temperatures.

 

[MattR]

Welcome to PF Matt. We prefer it if you include a link to what you have been reading. Please post the link before we answer.

Sure no problem.
https://en.wikipedia.org/wiki/Superconducting_magnet#Persistent_mode
Go down until persistent mode. The end of that paragraph reads:

"The winding current, and the magnetic field, will not actually persist forever, but will decay slowly according to a normal inductive (L/R) time constant:
H ( t ) = H 0 e − ( R / L ) t
where R is a small residual resistance in the superconducting wingdings due to joints or a phenomenon called flux motion resistance. Nearly all commercial superconducting magnets are equipped with persistent switches."

SMES links:
https://www.windpowerengineering.com/electrical/power-storage/say-hello-smes-superconducting-magnetic-energy-storage-system/
https://en.wikipedia.org/wiki/Superconducting_magnetic_energy_storage
https://www.technologyreview.com/s/423227/superconducting-magnets-for-grid-scale-storage/