From Ground Power to Green Apron: How Smart 400 Hz & 28 VDC Systems Are Enabling Airport Electrification

The aviation industry is moving through a historic transformation.

While global air traffic continues to rise, airports face new mandates: reduce emissions, modernise infrastructure, and maintain efficiency under growing pressure. The next generation of airports will be defined not only by aircraft in the air — but by how sustainably they operate on the ground.

Electrification of the apron is at the core of this shift, and smart ground power infrastructure — the silent backbone of every turnaround — is becoming the key enabler.

The Infrastructure Gap Behind “Green” Ambitions.

Across Europe and the Middle East, airport operators are investing heavily in electric ground support equipment (e-GSE): tow tractors, passenger buses, GPUs, PCA units, and service vehicles.

Yet many electrification programmes stumble on one hidden challenge — infrastructure.

Transitioning to a “green apron” requires far more than replacing diesel vehicles with electric ones. It demands a reliable, intelligent 400 Hz / 28 VDC power network that can serve aircraft and e-GSE fleets simultaneously without instability, overload, or downtime.

Legacy ground power systems were built for a different era — short cable runs, predictable loads, mild climates.

Today’s airports operate in extreme environments: the heat of Riyadh or Jeddah, the humidity of Casablanca, the frost of Northern Europe.

The result? Voltage drops, unstable frequency, overheating, and higher maintenance costs.

Without smart, efficient power delivery, the full benefits of apron electrification simply can’t be realised.

Why 400 Hz & 28 VDC Still Matter

While most attention focuses on electric vehicles, it’s the 400 Hz and 28 VDC systems that keep aircraft and support operations alive during turnaround.

400 Hz AC powers aircraft avionics, lighting, and cabin systems when engines are off.

28 VDC provides stable direct current for electronic control units, sensors, and maintenance operations.

Any fluctuation here affects not only comfort but safety and maintenance cycles.

As energy demands grow — with longer cable runs and more simultaneous aircraft connections — these power systems need to become smarter, stronger, and cleaner.

The Shift to Smart Ground Power

Modern ground power units are no longer just electrical boxes; they are intelligent energy nodes.

Integrated with digital controls, data monitoring, and automated protection, they balance performance and sustainability.

The latest generation of CDR Technology 400 Hz frequency converters and 28 V rectifiers illustrates how this evolution works in practice:

Automatic voltage drop compensation for cable lengths up to 200 m, ensuring steady voltage at the aircraft plug.

Precision frequency control (400 Hz ± 0.01 Hz) for clean, reliable power.

Wide temperature range –55 °C to +55 °C and humidity tolerance up to 100 %, protected by IP55 enclosures and anti-condensation systems.

Energy monitoring and log storage (up to 10 000 events) for predictive maintenance and transparency.

Modular design allowing key components to be replaced in under 10 minutes, reducing downtime and cost of ownership.

Each of these features directly supports the airport’s sustainability and reliability goals — by extending equipment lifetime, cutting energy losses, and improving operational efficiency.

Efficiency Through Cooling and Design.

One of the least visible but most important enablers of performance is thermal management.

Every kilowatt lost as heat reduces system efficiency and component lifespan.

Advanced cooling architecture — from dual-bearing fans to optimized air channels and heat sinks — is now becoming a competitive differentiator.

Efficient cooling means:

Lower power loss and noise level.

More stable output under heavy loads.

Reduced maintenance and higher uptime.

For airports operating in high-temperature regions like Saudi Arabia or North Africa, these design elements are not optional — they define whether an electrified gate truly works year-round.

The New Energy Currency.

As airports evolve into energy-aware ecosystems, data visibility becomes essential.

Modern GPUs and rectifiers equipped with SCADA / Modbus / TCP-IP interfaces allow operators to track consumption, predict maintenance, and optimise grid usage.

This real-time insight enables:

Smarter scheduling of e-GSE charging.

Detection of abnormal loads before they cause faults.

Accurate CO₂ and kWh reporting for sustainability audits.

In other words, you can’t manage what you can’t measure — and smart ground power systems finally make it measurable.

Global Push: Europe & Middle East

Europe: Programmes like ACI Europe’s Net Zero 2050 initiative and airport-specific “green apron” projects (Paris CDG, Frankfurt, Schiphol) prioritise fully electrified ground operations. Reliable 400 Hz infrastructure is a prerequisite for connecting electric GSE and aircraft simultaneously.

Middle East: Under Vision 2030, Saudi Arabia’s aviation sector is rapidly expanding. With over 330 million passengers projected by 2030, airports are scaling up infrastructure for heat-resistant, high-capacity, energy-efficient systems. CDR’s designs — tested up to +55 °C and high dust exposure — fit directly into that mission.

North Africa: Morocco’s ONDA “Airports 2030” programme modernises hubs such as Casablanca CMN. Electrified gates require 28 V and 400 Hz power with monitoring and modularity — again, the area where next-generation systems make the difference.

The Business Case: Reliability = ROI

Sustainability goals are important, but airport management still thinks in ROI.

Smart 400 Hz / 28 VDC systems justify investment through tangible results:

Reduced downtime via modular maintenance.

Lower OPEX through efficient cooling and energy recovery.

Extended lifecycle due to component protection and diagnostics.

Predictable operations — no unplanned outages or flight delays.

For large hubs, even a 1 % improvement in uptime or efficiency can save hundreds of thousands of euros annually.

The Path Forward

The transformation from Ground Power to Green Apron will not happen overnight.

It requires strategic investment, standardisation, and collaboration between OEMs, airports, and regulators.

But the direction is clear: electrified, data-driven, modular, and sustainable systems will power the next generation of airports.

Ground power equipment — once considered background infrastructure — is now a central player in achieving Net Zero aviation.

At CDR Technology, we believe reliability and innovation must coexist.

Our mission is simple: to deliver smart, efficient, and sustainable power systems that keep the world’s airports moving — cleaner, faster, and safer.

✈️ CDR Technology — Smart Ground Power for the Green Apron Era