What is a Solid-state Ground Power Unit?

Solid-State Ground Power Unit 

A solid-state ground power unit is used to supply power to an aircraft while it is parked. When the engines are off, it converts grid electricity into the power the aircraft needs, so onboard systems can keep running during maintenance, checks, and ground operations.

What it does

It takes standard grid power and converts it into:

· 115V / 400Hz AC, used by most onboard systems

· 28V DC, which can also support engine start

Stable output

The power is steady and clean, which helps protect onboard electronics from voltage swings and interference.

Efficient

Energy loss during conversion is low, so it makes good use of grid power and keeps operating costs down.

Quiet and clean

It runs with very little noise and produces no exhaust.

Easy to maintain 
Maintenance is straightforward. Mostly routine checks and replacing common parts. Costs depend on how often it’s used, but generally not high.

Where you see it

At the gate
Used at fixed stands where grid power is available. It keeps the aircraft powered during turnaround, cleaning, and loading.

In hangars
Used during maintenance and testing. The stable output is important, especially when working on sensitive systems.