# Superconducting magnetic storage

Energy held in the magnetic field of a superconducting coil.

Source page: https://www.materialinsights.org/energy/e_smes/

Storage · Electrical and system · No. 93

- Storage
- Duration: Seconds
 Storage · Electrical and system · Foundation · Energy

Current can circle a superconducting coil almost forever with no loss, ready to release its energy in about 5 milliseconds.

Chart: Illustration: Superconducting magnetic storage

##### Where it comes from

Chart: Map of where it comes from

Wire made of niobium alloys or rare-earth tape loses all resistance when chilled, so current circulates and stores energy in the magnetic field.

##### Three things to know

1. At 10 tesla a magnetic field holds only about 11 kWh per cubic metre, so SMES stores little energy.
2. Cooling to 4 K costs at least 74 W of input for every watt removed, even for an ideal refrigerator (calculated).
3. Superconducting tape cost USD 150 to 200/kA-m in 2023, against USD 50 seen as the tipping point for power uses.

##### The journey

1. 1 **DC power**Driven into a superconducting coil
2. 2 **Deep cold**Coil cooled to between 4 and 77 K
3. 3 **Circulating current**Flows with almost no resistance
4. 4 **Converter**Draws current out in milliseconds
5. 5 **Grid**Voltage support and power quality

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## Other sections

- [Overview](https://www.materialinsights.org/energy/e_smes/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_smes/correlation/index.md)
- [Science and technology](https://www.materialinsights.org/energy/e_smes/sg-sci/index.md)
- [Engineering and performance](https://www.materialinsights.org/energy/e_smes/sg-eng/index.md)
- [Economics](https://www.materialinsights.org/energy/e_smes/sg-econ/index.md)
- [Impact and additionality](https://www.materialinsights.org/energy/e_smes/sg-impact/index.md)
- [What to track](https://www.materialinsights.org/energy/e_smes/tracking/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_smes/links/index.md)