Air turns to liquid when refrigerated to -196 ° C , which is usually achieved by a cycle of compression , cooling and expansion , it can then be stored in conventionally insulated , ambient pressure vessels at very large scale . Exposure to ambient temperatures causes rapid re-gasification and a 700-fold expansion in volume , which is used to drive a turbine and create electricity .
Several years ago , WEG took part in a project designed by Highview Power Storage , to deliver the world ’ s first full scale LAES .
MAKING LAES OPERATIONAL
Highview Power Storage ’ s technology drew from established processes
from the turbo-machinery , power generation and industrial gas sectors .
Stuart Nelmes Head of Engineering at Highview explained , “ The beauty of this system is that each component part of the process is built using tried and tested technology , which we know works and has established performance parameters . The centrifugal fans sourced from Halifax Fan , one of the UK ’ s leading suppliers , driven by WEG motors , one of the worlds most recognised brands , therefore fitted our remit very closely .”
“ The LAES system comprises of three primary processes : a charging system , an energy store and a power recovery stage ,” Nelmes continued “ The energy efficiency of each stage is crucial to the economic viability of the project . Because we have to power the system with the electricity we generate or buy it from the grid the energy efficiency of each component is very important .”
“ Halifax has developed its centrifugal range to maximise energy efficiency and WEG offers a very energy efficient IE3 motor as standard so this also influenced our decision . Every little helps in this situation .”
The energy storage plant uses the same principle used to make your kitchen fridge cold — but more akin in scale to the effect you see freezing moisture in the air creating slabs of ice that crack off the surface of a space rocket as the fuel tanks empty . In the aforementioned project , Highview needed a very reliable , wellproven blown air solution to regulate the temperature and airflow around some of the key components in the system and so the Halifax Fan / WEG combination was a good option .
In addition , WEG ’ s after sales service and extensive support network could ensure that the technology would be reliable for years to come .
GREEN MACHINES
A key benefit of LAES are their green credentials . Once constructed , the commercial installations will be close to environmentally neutral , as the output is simply air . Or in the case of this test unit , inert Nitrogen supplied by BOC , which makes up 78 per cent of the atmosphere .
LAES are very effective for storing energy from renewable sources such as wind turbines , solar panels and tidal pools . Particularly , when there is a grid surplus as it provides a method to store and then feed energy back into the grid when demand peaks .
These facilities have masses of potential for the future of energy storage . And as the world continues to aim towards ambitious emission reduction targets and renewable energy goals , energy storage will become a crucial mechanism of balancing energy supply and demand .
More information on WEG and its support and experience in energy storage , generation and other power related projects , please visit www . weg . net
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