Energetix Pnu Power has developed a range of compressed air batteries as direct replacements for conventional battery and flywheel power backup/UPS systems, claiming lower carbon footprints, lower maintenance and reduced whole life costs. Industrial lead/acid batteries used for backup power are under challenge from these new energy efficient alternatives, running on air.
At the heart of each Pnu Power product is a scroll generator: a spiral pump of the type used for decades in superchargers and air conditioning units, but effectively running in reverse. The scroll drives a conventional generator to produce electricity on demand. Ultra capacitors and sophisticated electronic controls ensure that UPS power is delivered instantaneously.
Supplied as plug-and-play units from 3kW to 200kW, the batteries have already been deployed by users including National Grid in the UK and USA, together with international telecoms, aerospace and manufacturing companies. They can be driven from industry standard compressed air cylinders with an auto compressor for recharging, or plant mains air supplies.
Pnu Power has also developed a system specifically for data centre and larger UPS applications. Called the 1MVA Air-DRUPS™ (Compressed Air, Diesel, Rotary UPS), it uses a compressed air battery in place of rotary flywheel solutions to provide backup power. The containerised package includes a diesel generator and can be scaled up to 3MVA.
“Compressed air batteries are simply a smarter choice for most backup and UPS applications. Rotary flywheel based systems have significant power losses in standby mode and normal batteries require regular maintenance to ensure reliable operation,” said Pnu Power product manager Andrew Goodwin.
“By contrast, compressed air batteries use negligible power on standby, are virtually maintenance free, with a minimum 20 year service life and are totally dependable. They instantly deliver 100% of the UPS power required and in larger systems they greatly reduce the need for diesel generator starts caused by short outages.”
Mr Goodwin added: “The carbon footprint of data centres is increasingly a matter of concern. They consume more than 3% of electricity in the USA and their use of power is growing rapidly across the world. Compressed air batteries are a smarter choice because they are significantly more energy efficient than older UPS/backup technologies.”