# Capacitor Bank: Learn the Purpose, Cost, and Lead Time to Procure

#### Purpose of capacitor bank

Capacitors consume active power and release reactive power. They also present a low impedance to harmonics; in other words, they attract harmonic frequencies. Thus, they are installed in substations to:

• Correct power factor, consequently minimizes voltage drop at the load end, by injecting reactive volt-amp a.k.a. VARs.
• Minimize voltage fluctuations, typically generated near industrial facilities, using harmonic filter banks – improving power quality in the process.
• Capacitors are an integral piece of Flexible AC Transmission (FACT) device. Some of the FACT devices are:
1. Static Var Compensator: Used to provide reactive power support (either consume VARS using inductors or release VARs using capacitors – each device plugged into the circuit using thyristor valves) and to filter out harmonics
2. Series capacitors on high voltage transmission line: Used to maximize power flow on the line by consuming lagging VARs, improve the steady-state and dynamic stability of the power system (by preventing the generators from operating at the maximum allowable power angle. Learn more)

#### Cost of capacitor bank

Cost depends on the MVAR rating and whether it is an indoor or outdoor unit.

• 12kV 4MVAR capacitor in a metal-clad switchgear: ~$70,000 • 34.5kV 10.8MVAR capacitor in a metal-clad switchgear: ~$170,000
• 69kV 14.4MVAR capacitor fuseless outdoor type: ~$75,000 • 138kV 65MVAR capacitor fuseless outdoor type: ~$180,000
• 230kV 100MVAR capacitor fuseless outdoor type: ~$250,000 • 345kV 150MVAR capacitor fuseless outdoor type: ~$400,000
• 500kV 230MVAR capacitor fuseless outdoor type: ~\$700,000

#### Lead time to procure capacitor bank

~25 weeks

Information on cost and lead time is for your general knowledge only. Contact vendor with your equipment specifications for actual figures.

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Substation Major Equipment

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