 | This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages)
|
| Specific energy | 4–40 kJ/kg 1–10 W·h/kg[1] |
|---|---|
| Energy density | less than 40 kJ/L[1] |
| Specific power | ~10000–100000 kW/kg[1] |
| Charge/discharge efficiency | 95%[1] |
| Self-discharge rate | 0%[1] |
| Cycle durability | Unlimited cycles[1] |
Superconducting magnetic energy storage (SMES) systems store energy in the magnetic field created by the flow of direct current in a superconducting coil that has been cryogenically cooled to a temperature below its superconducting critical temperature. This use of superconducting coils to store magnetic energy was invented by M. Ferrier in 1970.[2]
A typical SMES system includes three parts: superconducting coil, power conditioning system and cryogenically cooled refrigerator. Once the superconducting coil is energized, the current will not decay and the magnetic energy can be stored indefinitely.
The stored energy can be released back to the network by discharging the coil. The power conditioning system uses an inverter/rectifier to transform alternating current (AC) power to direct current or convert DC back to AC power. The inverter/rectifier accounts for about 2–3% energy loss in each direction. SMES loses the least amount of electricity in the energy storage process compared to other methods of storing energy. SMES systems are highly efficient; the round-trip efficiency is greater than 95%.[3]
Due to the energy requirements of refrigeration and the high cost of superconducting wire, SMES is currently used for short duration energy storage. Therefore, SMES is most commonly devoted to improving power quality.
- ^ a b c d e f Superconducting Magnetic Energy Storage: Status and Perspective. Archived 2015-12-11 at the Wayback Machine Tixador, P. Jan 2008
- ^ SMES webpage, Université Paris-Saclay, https://hebergement.universite-paris-saclay.fr/supraconductivite/supra/en/applications-electricite-smes.php
- ^ Cheung K.Y.C, Cheung S.T.H, Navin De Silvia R.G, Juvonen M.P.T, Singh R, Woo J.J. Large-Scale Energy Storage Systems. Imperial College London: ISE2, 2002/2003.