Compressed air battery
Encyclopedia
A compressed air battery
stores energy in the form of compressed air
and uses it to generate electricity.. A compressed air battery uses air to drive a scroll expander or other device, which in turn drives a conventional generator, to produce electricity. They are used for standby and UPS
applications by several industries, including data center
s, and have been proposed for use in automobiles.
, which drives a conventional electricity generator to produce AC or DC current.
The first commercially available compressed air batteries were developed and launched under the Pnu Power brand in 2009 as alternatives to traditional batteries, for industrial applications including standby and Uninterruptible Power Supply (UPS)
. In 2008/9 these batteries were adopted by companies including National Grid (UK), Telecom Italia (Italy), Eskom (South Africa), ATK (USA) and Harris (USA) Applications include an installation at ATK, which uses surplus compressed air to generate electricity and feed it into the site’s power grid.
There are also available standardised plug-and-play compressed air batteries, in capacities of 3, 5, 10, 20, 100 and 200 kW, and containerised 1MVA Compressed Air Diesel Rotary UPS Systems Air-DRUPS, as a direct competitor for larger traditional battery and large rotary (DRUPS / Flywheel) solutions. As these systems have no moving parts in standby mode, it offers significantly greater energy efficiency which increases reliability and reduces standby losses leading to an overall higher efficiency system and lower carbon emissions than flywheel UPS solutions.
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
stores energy in the form of compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
and uses it to generate electricity.. A compressed air battery uses air to drive a scroll expander or other device, which in turn drives a conventional generator, to produce electricity. They are used for standby and UPS
Uninterruptible power supply
An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails...
applications by several industries, including data center
Data center
A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems...
s, and have been proposed for use in automobiles.
History
UK company Energetix Pnu Power was granted patents in Europe(2006), China (2008) and the USA (2010), for the principle of using compressed air to turn a scroll expanderScroll compressor
A scroll compressor is a device for compressing air or refrigerant...
, which drives a conventional electricity generator to produce AC or DC current.
The first commercially available compressed air batteries were developed and launched under the Pnu Power brand in 2009 as alternatives to traditional batteries, for industrial applications including standby and Uninterruptible Power Supply (UPS)
Uninterruptible power supply
An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails...
. In 2008/9 these batteries were adopted by companies including National Grid (UK), Telecom Italia (Italy), Eskom (South Africa), ATK (USA) and Harris (USA) Applications include an installation at ATK, which uses surplus compressed air to generate electricity and feed it into the site’s power grid.
There are also available standardised plug-and-play compressed air batteries, in capacities of 3, 5, 10, 20, 100 and 200 kW, and containerised 1MVA Compressed Air Diesel Rotary UPS Systems Air-DRUPS, as a direct competitor for larger traditional battery and large rotary (DRUPS / Flywheel) solutions. As these systems have no moving parts in standby mode, it offers significantly greater energy efficiency which increases reliability and reduces standby losses leading to an overall higher efficiency system and lower carbon emissions than flywheel UPS solutions.
Design
Compressed air batteries are often supplied as complete "plug and play" installations, in weatherproof enclosures. The principal components are:- Compressed air supply: either from cylinders or a plant’s compressed air mains
- Air flow controller to ensure precise metering of air supplied to the power train
- Power train comprising: a scroll expander (ref scroll expander), generator and rectifier/converter. As a scroll expander is effectively the same as a scroll compressor (or scroll pump), the technology is well proven and understood.
- Auto compressor to top up the air supply after it is depleted
- Control electronics
Features
- Maintenance of compressed air batteries is confined to an annual inspection
- There are no moving parts in standby mode
- Standby losses are confined to the running of the control electronics (<100W)