Equipmake hybrid power unit enters machine testing

Equipmake has moved Project Coeus into machine testing, with the hybrid industrial power unit now being installed in a Terex Ecotec TDS 820 shredder for trials at Perkins’ proving site.

The three year programme is led by Perkins with Equipmake and Loughborough University’s Wolfson School of Mechanical, Electrical and Manufacturing Engineering. It is developing a hybrid industrial open power unit intended as a replacement for a conventional diesel package in off-highway machinery.

The system combines a Perkins engine configured for spark ignition with a bespoke heavy duty Equipmake electric motor, silicon carbide inverter, and associated power electronics. It can be configured for hydrogen, ethanol, methanol, or biomethane, giving the development programme several fuel routes while retaining electrical hybrid assistance.

All four fuels selected for Project Coeus use spark ignition in this application. Perkins has developed a configurable combustion platform around that requirement, while the electric machine adds torque when the duty cycle demands it. That combination is intended to reproduce the power delivery needed by heavy off-highway machines without forcing an equipment manufacturer to redesign the complete installation around a different propulsion architecture.

The Terex shredder moves the project beyond test cell development. Once installation is complete, Perkins plans to assess whether the power unit can meet the machine’s peak load and transient response requirements under operating conditions that impose rapid changes in torque demand rather than a steady laboratory load.

Transient response is one of the engineering reasons for the hybrid architecture. Perkins says its hydrogen combustion system requires careful management of airflow and turbocharger response, whereas the electric machine can provide torque almost immediately. The hybrid system can therefore supplement the engine during short demand peaks while the combustion side reaches the required operating point.

Perkins’ current hydrogen configuration is based on its 1200 Series platform. The company states a total hybrid output of 379kW and 1,938Nm between 1,200 and 1,500rpm, combining the engine with the integrated motor generator unit. Those figures describe the current hydrogen demonstrator rather than every possible fuel configuration.

Equipmake supplies the heavy duty motor and silicon carbide inverter. An inverter switches semiconductor devices at high speed to control voltage, current, and torque in the electric machine. Silicon carbide devices can support high switching frequencies and temperatures in suitable designs, helping power electronics engineers manage losses, cooling requirements, and component size.

The motor and inverter cannot operate independently of the combustion engine. Control software has to determine how much torque each element contributes, when electrical assistance is required, and how battery state of charge is maintained over a working cycle. The strategy also has to protect equipment from thermal and electrical limits during repeated high load events.

Perkins has also developed a hybrid cooling arrangement around the demonstrator. Its current technical material describes separate cooling circuits with an electrically driven fan for charge cooling and a viscous drive fan on the main radiator, allowing cooling demand to be adjusted instead of running every fan at maximum requirement continuously.

Fans consume power and create noise, so matching cooling effort more closely to actual thermal demand can reduce unnecessary parasitic load. Machine testing will show whether the cooling system can maintain temperatures when the shredder moves repeatedly between lighter operation and peak load events.

Project Coeus is supported by £11.14m of UK Government funding through the Advanced Propulsion Centre, including £3.24m awarded to Equipmake. The funding supports the joint Perkins, Equipmake, and Loughborough University development programme rather than a production contract for the demonstrator itself.

The project made its first public appearance at CONEXPO-CON/AGG in March 2026 after extensive development testing. Perkins described the next phase as bringing the engine, hybrid system, cooling package, and associated components together before installing the complete power unit in a machine for testing.

The TDS 820 provides a demanding application because shredding loads can vary with material feed and resistance at the cutting system. A power unit has to tolerate those changes without unacceptable loss of speed, overheating, or control instability, making the application a useful test of the hybrid system’s transient capability.

Fuel flexibility creates additional engineering variables. Hydrogen, ethanol, methanol, and biomethane differ in storage, energy density, and combustion behaviour, so a configurable engine cannot assume identical fuelling and control conditions. Project Coeus addresses the power system on the machine rather than the upstream availability or lifecycle emissions of each fuel.

The programme also stops short of proving production readiness. Passing machine tests would establish that the prototype power unit can perform in a representative application, but industrialisation would still require durability validation, manufacturing engineering, service procedures, emissions certification where applicable, and integration support for different original equipment manufacturers.

Moving into the Terex shredder is therefore a distinct engineering milestone rather than a product launch. The engine, electric machine, inverter, cooling system, and controls now have to operate as one power unit under machine loads, providing the evidence needed before the architecture can progress towards wider off-highway deployment.