Compressed air is heart of UPS for data centre
The whole-life costs of the UPS system for the major data centre in the Pyramid building of the Co-operative Bank in Stockport have been much reduced by using compressed air and ultra-capacitors to store standby energy, rather than a battery system. The Air-DRUPS critical-power solution replaces scores of lead-acid batteries.
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| Look, no batteries. Uninterruptible power for a Co-operative Bank data centre in Stockport is provided by ultra-capacitors and quick-starting scroll generators driven by compressed air until the main standby generators have started. |
In the event of mains failure, power is initially provided by the ultra-capacitors for the short time it takes compressed-air scroll generators to respond to the demand. The compressed-air supply can meet demand for sufficiently long to give the main standby generators enough time to try starting at least once.
The compressed-air scroll generators that form the heart of the system are designed and made by Pnu Power in the UK, part of Energetix Group.
Compressed air is stored in cylinders at 300 bar, and the system has no moving parts in standby mode. Maintenance requirements are minimal compared to batteries. The system includes an air compressor to maintain pressure in the cylinders.
This project is said to be the first major data in the world to use a compressed-air system to supply back-up power.
The system is the result of collaboration between several companies. It combines VFI UPS technology and compressed-air generators from PNU Power, The system was installed and commissioned by DC Environmental Services.
Martyn Hulme, managing director Co-operative Estates, said:, ‘We are always looking at ways in which we can reduce our carbon footprint and so when our uninterruptible power supply (UPS) was up for renewal we wanted to find a greener system that would make the lead acid batteries obsolete.
‘This is the first time this compressed-air system has been used in this way, and we are confident that others will follow our lead.
‘The initial capital outlay is comparable to similar UPS systems although higher than those using batteries, but the total cost over the lifetime of the product is much lower, making it highly attractive.’
