High voltage power and cooling tower package

HV power and cooling tower solution helps commission compressor


When Howden Compressors produced the largest oil injected screw compressor in the world, they called on Aggreko's expertise to provide power and cooling to test it on site.

Howden Compressors identified they did not have sufficient site power or cooling in order to start and test the compressor or to reduce its temperature during the testing process.

Aggreko was asked to provide primary high voltage power for the main drive motor and supplementary cooling to cool the lube oil from 110°C to 50°C. 


After consultations, Aggreko’s high voltage and temperature control teams used their expertise and experience to design the most effective solution for both the power and cooling requirements.

For the power solution a ‘soft start’ option was preferred. 6 x 1250 kVA container generators with a step up 6 kV transformer were installed outside of the factory. This provided the 6mva of high voltage power required to start the motor and for the continuous testing. 

The cooling solution required 3 MW of supplementary cooling. Howden already had an existing cooling system with a capacity of 1 MW, consisting of a plate and frame heat exchanger and cooling tower.  Aggreko therefore provided an additional 3 MW to produce the 4 MW duty required for testing.

Aggreko did this by passing approximately 80% of the lube oil through two shell and plate heat exchangers in series.  The remaining 20% went through the site’s existing system.  Cooling water from a single modular Aggreko cooling tower system was passed through the other side of the heat exchangers to take the heat away.  

The system was kept operationally efficient and therefore cost effective by providing enough heat-transfer area (two heat exchangers) so that only one single cooling tower was required.   

The heat exchangers were placed inside of the building near the compressor test rig. The cooling tower and pump were located outside.


Aggreko has established a good working relationship with Howden Compressors.  The team was able to design, install and service a cost-effective solution that provided supplementary power and cooling over a seven week period.

Aggreko delivered an efficient and cost effective solution to give us the additional power and cooling we required. The team provided expert advice and the equipment proved very reliable.

Billy Miligan

Lead Electrical & Control Engineer, Howden Compressors